Circles: radius, diameter, circumference and Pi | Geometry | Khan Academy

Courses on Khan Academy are always 100% free. Start practicing-and saving your progress-now: www.khanacademy.org/math/cc-s...
A circle is at the foundation of geometry and how its parts relate to each other is both completely logical and a wonder.
Practice this lesson yourself on KhanAcademy.org right now:
www.khanacademy.org/math/geom...
Watch the next lesson: www.khanacademy.org/math/geom...
Missed the previous lesson?
www.khanacademy.org/math/geom...
Geometry on Khan Academy: We are surrounded by space. And that space contains lots of things. And these things have shapes. In geometry we are concerned with the nature of these shapes, how we define them, and what they teach us about the world at large--from math to architecture to biology to astronomy (and everything in between). Learning geometry is about more than just taking your medicine ("It's good for you!"), it's at the core of everything that exists--including you. Having said all that, some of the specific topics we'll cover include angles, intersecting lines, right triangles, perimeter, area, volume, circles, triangles, quadrilaterals, analytic geometry, and geometric constructions. Wow. That's a lot. To summarize: it's difficult to imagine any area of math that is more widely used than geometry.
About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to Khan Academy’s Geometry channel:
/ channel
Subscribe to Khan Academy: czcams.com/users/subscription_...

[@thesaaturn]

Me and the bois whatching khan academy in quarantine

[@shrekster5713]

me and the boys watching khan academy during the second quarantine ;(

[@BilalAli-rh2cx]

Shrekster5 lol

[@stephenbrown1878]

hey does anyone does zooms for this type of math?

[@christophergonzalez8883]

@@shrekster5713 lol same here man

[@Ethan-pu5lo]

Noice

[@canuseetheuglybirdie6599]

just want to know how he can write perfectly on desktop

[@AngelFire-gh8dw]

Hes probably been doing it for awhile

[@floridmonkey2723]

I thought he used a Wacom tablet too.

[@danellet1365]

He uses some sort of drawing drawing tablet.

[@blakezabala3846]

He uses a not pad and uses a special pen. I thought how he wrote awesome too...he is using almost like a Promethean board.

[@animationspace8550]

Like dis? π< a perfict piez

[@michaelmag1095]

Another excellent explanation from khan academy. Explaining how the formula was originally established makes it so much easier to comprehend.

[@ashleyrojas6419]

im too dumb and i have a test tommrow that determines. my future

[@Raddrizz]

How'd it go?

[@florpbosh3079]

Yeah how did it go

[@nia.r5988]

How'd it go?! We wanna knowww

[@florpbosh3079]

@@nia.r5988 he probly not gonna anwser 😂😂why it sound like a sentence when i said ur name wit my text

[@prastuti4264]

How did ur test go Ashley??
Probably you got an F

[@nathanielackman1019]

i think i did a funny,
teacher: king arthur invented the circle table.
Student: no it was sir cumference.

[@Mars_-mi4di]

Nathaniel Ackman lol

[@channingnicholson4275]

Mel c lol to you too dude hahahahhahaha

[@maheenFahad]

U talkin about pac-man

[@wrec6367]

Dinkleburg

[@Sansatu23]

you are literally the greatest person alive. You saved me from a F in my math class

[@Lily-mm8ew]

Because of online school I went from an 100 in math to a 0 looll and sadly these aren’t helping rip

[@alaadarwiche4352]

Lily lol I can already see! They don’t say “an 100” they say “a 100”!
I use to take 💯 to! But now, I am at 95😔😔. But I am trying my best!

[@huyuht]

help me

[@Lily-mm8ew]

tarek nigeria bruv what? I ain’t ever heard anyone say “a a hundred”

[@nikkiblack6546]

@@Lily-mm8ew right

[@rainstorm.]

Omg bless u I have a circle geometry test tomorrow

[@kakashihatake1376]

Blue Pearl same here

[@zeleakatjingisiua4234]

I'm obviously writing Friday or next week Monday imagine that

[@afrazmustofa3814]

same

[@sheliadavis4901]

I have to do a scale model of Pluto😰👿😢

[@RandomPerson-sh5uv]

Blue Pearl same

[@crbaade]

As a mom trying to homeschool in 2021, this is so valuable. I love how he explains it step by step.

[@mariagarceteabea2748]

Who's scrolling down the comments while watching this 😂

[@priyasakhare9764]

Me 😒

[@subhaarul8025]

Meeeeeee

[@jenniferrivera6922]

me im soo bored

[@oliverwilliams4347]

me:p

[@risesthestars]

Maria Garcete Abea meee lol

[@thericefarmer2271]

Play at 0.5 speed if you want to hear a drunk man and start rolling on the floor laughing.

[@1017brody]

+DanTheCakeMan Haha

[@actuallyel8936]

+DanTheCakeMan
I am so doing this.

[@actuallyel8936]

+DanTheCakeMan
To get creepy-crazy-fast math geek play at 2 or 1.25 or 1.5 xD

[@thericefarmer2271]

IcePlayzRolePlay AphmauFanFic xD Yeah I tried every speed. Lol. Love the new speed changer

[@uravrgmemer8177]

U bloody legend

[@ambercaesar4560]

The public school system has failed me greatly. It took me 24 years to fully understand something he explained perfectly in 11 minutes. Thank you Khan Academy!!

[@brandonseto4524]

I actually understood this in 10 minutes besides my math teacher

[@derickhernandez7123]

5:28 “they gave it a nut”

[@selenawright1332]

and this why we failing geometry 😂😂

[@ryanchong4372]

Thought no one noticed

[@Oofmart]

lmao

[@shruti4s745]

reasons why Im failing math😂

[@robloxrox9502]

🤣

[@kenyan3057]

Omg. I've been doing this for the last 5 yrs of my life and never understood and understood it by half way through th video

[@alaadarwiche4352]

I didn’t

[@stephenbrown1878]

Have you started understanding this math yet? I need help.

[@randomlotus8806]

Man, thanks. This helped, I don't know. My math teacher never explains right. No one in my class understands him. They all just learn the material on their own.

[@christylabarbera2921]

I'm a 55 year old college student who has always been horrible at math just trying to pass the Praxis. This is the best explanation of Pi ever!! After all these years, I understand. Thank you!!

[@penginator89]

wait what 💀 how are you 55 and still in college?

[@christycreates1731]

@@penginator89 Easy, I went to college late in life. Not everyone goes right after high school.

[@wowomgcreative]

thats like retireing age how did you just get to college

[@christycreates1731]

@@wowomgcreative I hope that's not a serious question. If you can't figure it out, maybe you need to go to college.

[@manuel5114]

@@wowomgcreative Here in Argentina most Universities are tuition free and open to everyone who graduted from high school, so there are many elderly people attending University. Of course there's no age restriction in paid Universities, but having to pay a tuition may be a deterrant.

[@pariswilliams2986]

thank you so much, you are the best teacher ever! with that 11 Minute video, you taught me more than I would have learnt in 2 lessons!

[@hausofamelia]

Wow, this made it seem much more simpler than it seemed to be! I finally understand, so thank you. :)

[@sophiarodriguez1861]

Khan is probably the BEST teacher ever!! thanks!

[@luxfries1524]

Organic chemistry is second best

[@arunjohny]

@@luxfries1524 Who is the best in organic chemistry?

[@amigo7672]

khan’s probably the teacher we’ve always wished for
but never got

[@kawaiipandajoy8101]

it really helped me catch up when I'm absent at school coz I'm always ill

[@idontknoe6454]

Kawaii PandaJoy same

[@splatty6863]

Can I get the snap

[@Brandon-sy2du]

Mmmmmmhmmm.... sureeee

[@alaadarwiche4352]

Same as my sister omg my sister has a twin lol 😂

[@andyh8700]

Awesome you made me understand so much better about the Circle, keep up the great work!

[@GrantDavis]

Almost to the point of acing my SAT practice tests, took geometry in 8th grade, this serves as just enough review for me to be proficient in it again.

[@oscarb1582]

Though I was able to follow this very easily I can understand why others can't

[@fantastic_fox0918]

Wdym if you’re saying this the way I think it’s just everyone learns at a different paste and there’s always something someone’s good at and then isn’t good at.

[@meyouweaboo1551]

@@fantastic_fox0918 did you read it?

[@fantastic_fox0918]

Me You Weaboo ohhhh sorry I thought you said can’t lol 😂 I was a little tired that day

[@whotheheckis_ray]

My teacher has been recently absent and we've had many substitute teachers come in which interrupted me and my classmates curriculum for math, when we got the lesson on Circles I had no idea what I was being assigned and thank you so much for this video teaching me more then school.

[@musicplaylists5440]

3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989380952572010654858632788659361533818279682303019520353018529689957736225994138912497217752834791315155748572424541506959508295331168617278558890750983817546374649393192550604009277016711390098488240128583616035637076601047101819429555961989467678374494482553797747268471040475346462080466842590694912933136770289891521047521620569660240580381501935112533824300355876402474964732639141992726042699227967823547816360093417216412199245863150302861829745557067498385054945885869269956909272107975093029553211653449872027559602364806654991198818347977535663698074265425278625518184175746728909777727938000816470600161452491921732172147723501414419735685481613611573525521334757418494684385233239073941433345477624168625189835694855620992192221842725502542568876717904946016534668049886272327917860857843838279679766814541009538837863609506800642251252051173929848960841284886269456042419652850222106611863067442786220391949450471237137869609563643719172874677646575739624138908658326459958133904780275900994657640789512694683983525957098258226205224894077267194782684826014769909026401363944374553050682034962524517493996514314298091906592509372216964615157098583874105978859597729754989301617539284681382686838689427741559918559252459539594310499725246808459872736446958486538367362226260991246080512438843904512441365497627807977156914359977001296160Lol4If7You4See0This9You2Will6Be5A7Millionare43ᕕ(ᐛ)ᕗ8944169486855584840635342207222582848864815845602850601684273945226746767889525213852254995466672782398645659611635488623057745649803559363456817432411251507606947945109659609402522887971089314566913686722874894056010150330861792868092087476091782493858900971490967598526136554978189312978482168299894872265880485756401427047755513237964145152374623436454285844479526586782105114135473573952311342716610213596953623144295248493718711014576540359027993440374200731057853906219838744780847848968332144571386875194350643021845319104848100537061468067491927819119793995206141966342875444064374512371819217999839101591956181467514269123974894090718649423196156794520809514655022523160388193014209376213785595663893778708303906979207734672218256259966150142150306803844773454920260541466592520149744285073251866600213243408819071048633173464965145390579626856100550810665879699816357473638405257145910289706414011097120628043903975951567715770042033786993600723055876317635942187312514712053292819182618612586732157919841484882916447060957527069572209175671167229109816909152801735067127485832228718352093539657251210835791513698820914442100675103346711040841486377670096120715124914043027253860764823634143346235189757664521641376796903149501910857598442391986291642193994907236234646844117394032659184044378051333894525742399508296591228508555821572503107125701266830240292952522011872676756220415420516184163484756516999811614101002996078386909291603028840026910414079288621507842451670908700069928212066041837180653556725253256753286129104248776182582976515795984703562226293486003415872298053498965022629174878820273420922224533985626476691490556284250391275771028402799806636582548892648802545661017296702664076559042909945681506526530537182941270336931378517860904070866711496558343434769338578171138645587367812301458768712660348913909562009939361031029161615288138437909904231747336394804575931493140529763475748119356709110137751721008031559024853090669203767192203322909433467685142214477379393751703443661991040337511173547191855046449026365512816228824462575916333039107225383742182140883508657391771509682887478265699599574490661758344137522397096834080053559849175417381883999446974867626551658276584835884531427756879002909517028352971634456212964043523117600665101241200659755851276178583829204197484423608007193045761893234922927965019875187212726750798125547095890455635792122103334669749923563025494780249011419521238281530911407907386025152274299581807247162591668545133312394804947079119153267343028244186041426363954800044800267049624820179289647669758318327131425170296923488962766844032326092752496035799646925650493681836090032380929345958897069536534940603402166544375589004563288225054525564056448246515187547119621844396582533754388569094113031509526179378002974120766514793942590298969594699556576121865619673378623625612521632086286922210327488921865436480229678070576561514463204692790682120738837781423356282360896320806822246801224826117718589638140918390367367222088832151375560037279839400415297002878307667094447456013455641725437090697939612257142989467154357846878861444581231459357198492252847160504922124247014121478057345510500801908699603302Lol1If5You6See9This0You4Will7Kiss4Your2Crush4ᕕ(ᐛ)ᕗ76347870810817545011930714122339086639383395294257869050764310063835198343893415961318543475464955697810382930971646514384070070736041123735998434522516105070270562352660127648483084076118301305279320542746286540360367453286510570658748822569815793678976697422057505968344086973502014102067235850200724522563265134105592401902742162484391403599895353945909440704691209140938700126456001623742880210927645793106579229552498872758461012648369998922569596881592056001016552563756785667227966198857827948488558343975187445455129656344348039664205579829368043522027709842942325330225763418070394769941597915945300697521482933665556615678736400536665641654732170439035213295435291694145990416087532018683793702348886894791510716378529023452924407736594956305100742108714261349745956151384987137570471017879573104229690666702144986374645952808243694457897723300487647652413390759204340196340391147320233807150952220106825634274716460243354400515212669324934196739770415956837535551667302739007497297363549645332888698440611964961627734495182736955882207573551766515898551909866653935494810688732068599075407923424023009259007017319603622547564789406475483466477604114632339056513433068449539790709030234604614709616968868850140834704054607429586991382966824681857103188790652870366508324319744047718556789348230894310682870272280973624809399627060747264553992539944280811373694338872940630792615959954626246297070625948455690347119729964090894180595343932512362355081349490043642785271383159125689892951964272875739469142725343669415323610045373048819855170659412173524625895487301676002988659257866285612496655235338294287854253404830833070165372285635591525347844598183134112900199920598135220511733658564078264849427644113763938669248031183644536985891754426473998822846218449008777697763127957226726555625962825427653183001340709223343657791601280931794017185985999338492354956400570995585611349802524990669842330173503580440811685526531170995708994273287092584878944364600504108922669178352587078595129834417295351953788553457374260859029081765155780390594640873506123226112009373108048548526357228257682034160504846627750450031262008007998049254853469414697751649327095049346393824322271885159740547021482897111777923761225788734771881968711694147764214411112635835538713610110232679877564102468240322648346417663698066378576813492045302240819727856471983963087815432211669122464159117767322532643356861461865452226812688726844596844241610785401676814208088502800541436131462308210259417375623899420757136275167457318918945628352570441335437585753426986994725470316566139919996826282472706413362221789239031760854289437339356188916512504244040089527198378738648058472689546243882343751788520143956005Lol If You Got This Far Reply And Tell Me ᕕ(ᐛ)ᕗ

[@ilikefriedchicken6139]

Swag_Squad yasss i got far🎉🎉

[@whitedarkness3768]

Swag_Squad I got this far

[@blakezabala3846]

GOOD JOB!
3.141592653589793238462643383279502884197169399375105820974944592307816406286 208998628034825342117067982148086513282306647093844609550582231725359408128481 117450284102701938521105559644622948954930381964428810975665933446128475648233 786783165271201909145648566923460348610454326648213393607260249141273724587006 606315588174881520920962829254091715364367892590360011330530548820466521384146 951941511609433057270365759591953092186117381932611793105118548074462379962749 567351885752724891227938183011949129833673362440656643086021394946395224737190 702179860943702770539217176293176752384674818467669405132000568127145263560827 785771342757789609173637178721468440901224953430146549585371050792279689258923 542019956112129021960864034418159813629774771309960518707211349999998372978049 951059731732816096318595024459455346908302642522308253344685035261931188171010 003137838752886587533208381420617177669147303598253490428755468731159562863882 353787593751957781857780532171226806613001927876611195909216420198938095257201 065485863278865936153381827968230301952035301852968995773622599413891249721775 283479131515574857242454150695950829533116861727855889075098381754637464939319 255060400927701671139009848824012858361603563707660104710181942955596198946767 837449448255379774726847104047534646208046684259069491293313677028989152104752 162056966024058038150193511253382430035587640247496473263914199272604269922796 782354781636009341721641219924586315030286182974555706749838505494588586926995 690927210797509302955321165344987202755960236480665499119881834797753566369807 426542527862551818417574672890977772793800081647060016145249192173217214772350 141441973568548161361157352552133475741849468438523323907394143334547762416862 518983569485562099219222184272550254256887671790494601653466804988627232791786 085784383827967976681454100953883786360950680064225125205117392984896084128488 626945604241965285022210661186306744278622039194945047123713786960956364371917 287467764657573962413890865832645995813390478027590099465764078951269468398352 595709825822620522489407726719478268482601476990902640136394437455305068203496 252451749399651431429809190659250937221696461515709858387410597885959772975498 930161753928468138268683868942774155991855925245953959431049972524680845987273 644695848653836736222626099124608051243884390451244136549762780797715691435997 700129616089441694868555848406353422072225828488648158456028506016842739452267 467678895252138522549954666727823986456596116354886230577456498035593634568174 324112515076069479451096596094025228879710893145669136867228748940560101503308 617928680920874760917824938589009714909675985261365549781893129784821682998948 722658804857564014270477555132379641451523746234364542858444795265867821051141 354735739523113427166102135969536231442952484937187110145765403590279934403742 007310578539062198387447808478489683321445713868751943506430218453191048481005 370614680674919278191197939952061419663428754440643745123718192179998391015919 561814675142691239748940907186494231961567945208095146550225231603881930142093 762137855956638937787083039069792077346722182562599661501421503068038447734549 202605414665925201497442850732518666002132434088190710486331734649651453905796 268561005508106658796998163574736384052571459102897064140110971206280439039759 515677157700420337869936007230558763176359421873125147120532928191826186125867 321579198414848829164470609575270695722091756711672291098169091528017350671274 858322287183520935396572512108357915136988209144421006751033467110314126711136 990865851639831501970165151168517143765761835155650884909989859982387345528331 635507647918535893226185489632132933089857064204675259070915481416549859461637 180270981994309924488957571282890592323326097299712084433573265489382391193259 746366730583604142813883032038249037589852437441702913276561809377344403070746 921120191302033038019762110110044929321516084244485963766983895228684783123552 658213144957685726243344189303968642624341077322697802807318915441101044682325 271620105265227211166039666557309254711055785376346682065310989652691862056476 931257058635662018558100729360659876486117910453348850346113657686753249441668 039626579787718556084552965412665408530614344431858676975145661406800700237877 659134401712749470420562230538994561314071127000407854733269939081454664645880 797270826683063432858785698305235808933065757406795457163775254202114955761581 400250126228594130216471550979259230990796547376125517656751357517829666454779 174501129961489030463994713296210734043751895735961458901938971311179042978285 647503203198691514028708085990480109412147221317947647772622414254854540332157 185306142288137585043063321751829798662237172159160771669254748738986654949450 114654062843366393790039769265672146385306736096571209180763832716641627488880 078692560290228472104031721186082041900042296617119637792133757511495950156604 963186294726547364252308177036751590673502350728354056704038674351362222477158 915049530984448933309634087807693259939780541934144737744184263129860809988868 741326047215695162396586457302163159819319516735381297416772947867242292465436 680098067692823828068996400482435403701416314965897940924323789690706977942236 250822168895738379862300159377647165122893578601588161755782973523344604281512 627203734314653197777416031990665541876397929334419521541341899485444734567383 162499341913181480927777103863877343177207545654532207770921201905166096280490 926360197598828161332316663652861932668633606273567630354477628035045077723554 710585954870279081435624014517180624643626794561275318134078330336254232783944 975382437205835311477119926063813346776879695970309833913077109870408591337464 144282277263465947047458784778720192771528073176790770715721344473060570073349 243693113835049316312840425121925651798069411352801314701304781643788518529092 854520116583934196562134914341595625865865570552690496520985803385072242648293 972858478316305777756068887644624824685792603953527734803048029005876075825104 747091643961362676044925627420420832085661190625454337213153595845068772460290 161876679524061634252257719542916299193064553779914037340432875262888963995879 475729174642635745525407909145135711136941091193932519107602082520261879853188 770584297259167781314969900901921169717372784768472686084900337702424291651300 500516832336435038951702989392233451722013812806965011784408745196012122859937 162313017114448464090389064495444006198690754851602632750529834918740786680881 833851022833450850486082503930213321971551843063545500766828294930413776552793 975175461395398468339363830474611996653858153842056853386218672523340283087112 328278921250771262946322956398989893582116745627010218356462201349671518819097 303811980049734072396103685406643193950979019069963955245300545058068550195673 022921913933918568034490398205955100226353536192041994745538593810234395544959 778377902374216172711172364343543947822181852862408514006660443325888569867054 315470696574745855033232334210730154594051655379068662733379958511562578432298 827372319898757141595781119635833005940873068121602876496286744604774649159950 549737425626901049037781986835938146574126804925648798556145372347867330390468 838343634655379498641927056387293174872332083760112302991136793862708943879936 201629515413371424892830722012690147546684765357616477379467520049075715552781 965362132392640616013635815590742202020318727760527721900556148425551879253034 351398442532234157623361064250639049750086562710953591946589751413103482276930 624743536325691607815478181152843667957061108615331504452127473924544945423682 886061340841486377670096120715124914043027253860764823634143346235189757664521 641376796903149501910857598442391986291642193994907236234646844117394032659184 044378051333894525742399508296591228508555821572503107125701266830240292952522 011872676756220415420516184163484756516999811614101002996078386909291603028840 026910414079288621507842451670908700069928212066041837180653556725253256753286 129104248776182582976515795984703562226293486003415872298053498965022629174878 820273420922224533985626476691490556284250391275771028402799806636582548892648 802545661017296702664076559042909945681506526530537182941270336931378517860904 070866711496558343434769338578171138645587367812301458768712660348913909562009 939361031029161615288138437909904231747336394804575931493140529763475748119356 709110137751721008031559024853090669203767192203322909433467685142214477379393 751703443661991040337511173547191855046449026365512816228824462575916333039107 225383742182140883508657391771509682887478265699599574490661758344137522397096 834080053559849175417381883999446974867626551658276584835884531427756879002909 517028352971634456212964043523117600665101241200659755851276178583829204197484 423608007193045761893234922927965019875187212726750798125547095890455635792122 103334669749923563025494780249011419521238281530911407907386025152274299581807 247162591668545133312394804947079119153267343028244186041426363954800044800267 049624820179289647669758318327131425170296923488962766844032326092752496035799 646925650493681836090032380929345958897069536534940603402166544375589004563288 225054525564056448246515187547119621844396582533754388569094113031509526179378 002974120766514793942590298969594699556576121865619673378623625612521632086286 922210327488921865436480229678070576561514463204692790682120738837781423356282 360896320806822246801224826117718589638140918390367367222088832151375560037279 839400415297002878307667094447456013455641725437090697939612257142989467154357 846878861444581231459357198492252847160504922124247014121478057345510500801908 699603302763478708108175450119307141223390866393833952942578690507643100638351 983438934159613185434754649556978103829309716465143840700707360411237359984345 225161050702705623526601276484830840761183013052793205427462865403603674532865 105706587488225698157936789766974220575059683440869735020141020672358502007245 2256326513410559240190274216248439140

[@vasumalhotra4035]

U got it

[@dylanscott5412]

I got that far

[@aryanakularathne9467]

Wow, this made it seem much more simpler than it seem to be! I finally understand, thank you very much Sal!

[@Poli1348]

Great last minute studying before an exam. All said.

[@thanos6818]

This helped a lot but how does he write so good on desktop? I CANT EVEN WRITE GOOD ON PAPER, please help xd

[@sumanshekhawat3209]

Suck Thanos we like avengers

[@alchemy-the-animated-series]

Thanos I think he used a stylus

[@chloemacdonald9325]

@@alchemy-the-animated-series Wacom Tablet

[@lomaatmeh2854]

Thanos is trash and thor is the strongest avenger

[@Imgbycin]

Loma Atmeh no one cares

[@imanmarrianamontgomery6992]

Now I understand the area and circumfrance of a circle. YAY!!

[@imanmarrianamontgomery6992]

cool

[@Taybansss]

hey what grade u in

[@stephenbrown1878]

Wow i'm glad you understand I need a little help?

[@masteroids]

This is really helpful for my daughter in math class!!

[@GetJammed_]

This insanley helped me understand the things taht my teacher said to wait until it is time to learn it. Thanks so much Khan Academy!!!

[@pham6238]

Diameter is a line goes straight through the center of a circle
Radius is a line goes to half of a circle
Circumference is the distance around the circle
If you want to find circumference, get the diameter multiply by pi
EDIT: OMG GOT SO MICH LIKE THANK YOU

[@lydiasimpson586]

OMG THANK YOU SO MUCH I FINALLY FIGURED OUT A PROBLEM IVE BEEN STUCK ON FOR 40 MIN

[@razanabanana587]

listen to the circle song

[@brotherlance]

PopBAT thanks

[@tubeisace]

I wish they'd taught me like that in school! So easy to understand now! Thank you!

[@swisszz]

This comment is so old and this video too lol

[@azucena-hm2wo]

how are you doing now?

[@bitter-to-better]

Khan academy is probably the only videos I understand. Thanks so much I have a math exam tomorrow. This might seem dumb, but why do the call the length going around the circle circumference and not perimeter??

[@DJBailey99]

Thank you so much you saved me my week of lunch times and deducted a week of after school detentions! THANK YOUUUUUUUUUUU :)

[@vishrutkinikar2311]

Awesome video, Using this to prep for school Thank you!!!!!!!

[@timothygough789]

A go-to for instructional practices at any students pace.

[@alifhossain9463]

he is so smart this is helping me a lot he even does in my lauguage

[@gfdgf2]

you have just made clear to me what my math teacher had failed to specify for 12 years of school.
may god rain his blessings upon you.
p.s
r u related to ginghis by any chance?
thanks

[@Coleman469]

Very helpful. I forgot how to do this, so this helped!

[@abelmontoya3180]

"Some order to it all." God is good.

[@GamerRocket]

Well, in search for a video to help me out with Pi, this video did just that, in fact it went over expectations. Impressive :D

[@adiliamaxwell2992]

He is a good person he is not one of those people who wants subs he just wants to help. So keep up the good work.

[@alvindueck8227]

Ok. How would you get the circumference of an oval

[@talevaters0720]

still the same
bro

[@abdalrahmanamrmostafa1975]

@@talevaters0720 no

[@Z3R0C0NTENT]

Khan Academy is so useful and easy to understand!

[@MathDotCom]

It makes my concepts more clear for teaching my students

[@realyashshukla]

Thanks for giving your knowledge to us ❣️

[@nightcorenymph358]

You saved my grade. Why can't teachers talk like this? It gets their point across.

[@sssssunyy]

i love u guys sm . im in special education because i didnt go to 5th or 6th grade and im really behind . im still not on track yet but i’ve been reviewing lots of the important stuff from those 2 grades i missed . khan academy might actually save my future

[@bryannguyen8440]

This video helps me a lot and well explained

[@Minnielovelove]

thks so much i have to prepare for a maths test tomorrow and u helped me!

[@dougieladd]

I'm pretty useless with Math... this was a good explanation (in so far as I 'got it'). I would like to know more about how to move around the formula to get what you need... how that works, would be good. Thanks.

[@kenciolek843]

" O " occurs in the King James Bible over a thousand times

[@flameripple]

Thank you SOOOO much you SAVED my math homework!

[@wartortle577]

Confused..What if the question asks something like "Suppose the circumference of a circle is 7π. What is its diameter?"
They don't use the meter unit

[@jamaabdulle3050]

cos ur dumb

[@legendary436]

14 pie aka 14x3.14

[@minhaj283]

wartortle557 to work out any sort of question like this u need to know the basics of rearranging formulas. If u know 7π is the circumference then basically it is πxd=7π therefore diameter=7π/π which is of course 7. So 7 is the diameter. If there is no unit then just leave it as a bare number but almost all the time there is always a unit.

[@RachelKimJaceMordecai]

jama abdulle No need to be rude.

[@Ronie12]

jama abdulle Based by your typing and his typing....Your the dumb one XD

[@MrMoeqt]

An irrational constant which is the ratio between the circumference and the diameter. It has no end, and no repeats. It begins something like 3.1415... etc, it has an infinite amount of decimal places. We can only approximate pi to a certain number of decimals places, but a handy approximation of pi is 22/7. But another interesting fact about the number pi is that it can never be expressed perfectly as the ratio of two integers. We are able to make approximations like 22/7 but we can't be exact.

[@lunadreamystrz7875]

Currently watching this to help study for an upcoming test in my advanced math class, which I'm currently on the road to fail, but I hope this will help, I'll update if it does! :)

[@talevaters0720]

thanks man! i have an exam tomorrow :D LIKED!

[@denzelchang4607]

Thanks man
You saved me from repeating my year
I didnt understand my teacher because of the noise
But thank god i found your vid
Thanks alot!!!

[@Aynos11rules]

This was my reaction at 4:23 :O This is so cool!!!! I am in wonderment...

[@alyssarodriguez9639]

OMG.... This is helped me soooo much with mi homework!!!!! :)

[@necker-zs7yu]

Bro, I came back from school without understanding a thing that my teacher said I completely understand the subject and THANK YOU

[@metronini]

Thanks Sal for the help

[@chuman5103]

my geometry teacher really be sending us things we learned in 6th grade like we in high school I know this

[@asgharibegum465]

u are the best u saved my life
thnx

[@irkiIIer]

for the first time in my life i finally understand wtf pi is

[@brandonbrinker6592]

thx this helped alot

[@EspressoLegalPh]

please make some videos about geometry..
thanks for this vid btw
very very useful for our exam tomorrow ::D

[@tiaankreeft8156]

11 year old comment

[@youssefmallak8198]

this is really gonna help me get in to the high school i wanna go to

[@cookieplayz8703]

Your amazing sir ! Keep it up !

[@sidahmedbilalbilal6415]

this is legit the most helpful thing in the world, now i am not going to fail class

[@meyouweaboo1551]

Can't wait to use this information after I graduate

[@giraffequeen4110]

right? 😭

[@rebeccaw113]

Very helpful!!! Thanks!!

[@987654321breanna]

thanks soo much! i have this for homework and this helped alot!!!

[@spsindia2001]

wow this made me much more simpler than it seem thanku so much

[@LamePrincesss]

THANK YOU KIND SIR ❤️❤️

[@idontknoe6454]

I’m pretty sure that when time started they didn’t have tape measures and looked at the circumference and measured it and stuff and wrote down all the d= 2xr

[@user-rg8oe]

my exams tomorrow and I just noticed I don't know anything about this stuff! thanks!

[@munemmatin1284]

thanks man i passed this part on my test!

[@viennatung9145]

Thank you Khan Academy

[@px_chy6716]

Tysm now I’m not worried about my math essay anymore :D

[@Jayy642]

thank you for helping me study for my math test

[@amandacatalano461]

im in 7th grade and im struggling but this helps so much so thank you

[@shameemafarhana5201]

What curriculum is this?

[@blakezabala3846]

So there is pi, we just cant eat it :(

[@realseniourtaco5283]

Zabala lol

[@blakezabala3846]

xD

[@priyasakhare9764]

XD

[@spooktspeek]

if you write it on paper and then eat it you can eat pi.. but it isnt tasty.

[@literallythebestgamereverfr]

I love how I shouldn’t even be learning this yet but I am lol

[@ngarcia1995]

I love these video's! If my math tea her actually did her job instead of flirting with the boys ha

[@mylotraxlegacy5328]

This is amazing! I am in 4th grade and I love math, and since I am the smartest in my grade this video interested me a lot.

[@surusashikant6023]

I am in the fourth grade too.

[@surusashikant6023]

Very nice

[@jonnakatebariso5363]

thank you so much even doe this was posted when im not born yet

[@rawrdomo45]

Dude I totally understand now thanks!

[@anshkrishna857]

Sal, your voice is amazing!

[@mattchrisnickandchester]

The funny thing for me is that literally every math test I passed was because of Khan academy and all the tests i have failed was taught by my math teacher. THANK YOU.

[@TheSkaterdude789]

it is related cuz u have to multiply the diameter by 3.14 (which is PI) to get the circumference

[@UpulMathsacademy]

Good job done thanks lot...

[@apollogaming3428]

Thx so much I understand this much better now :)

[@musicmadjellybean]

LOL 'How fat is the circle?' Made me laugh. :)

[@hiramsimpson7838]

so easy to understand

[@kaitlyndai4290]

TANK U! this helped a lot :)

[@jamaabdulle3050]

its ok cutie

[@rahimabegum8739]

+jama abdulle creep...

[@lppulga7365]

Yeaahhhh thanks for sharing your idea i really easy learned that

[@melindadooley5731]

Thx dude, this was very helpfull

[@1995a1995z]

I love how you explained how pi was discovered