These Two (Directed) Angles Are The Same!

Geometry started off in Ancient Greeks, mainly of a subject, concerning lines and angles. And they give us different shapes like a triangle, square or even a circle. In this video, we will focus on the topic of angles and intuitively, we normally define angles to be non-negative. But have you ever thought of why there’s no negative angles? Since negative numbers do play a significant role in arithmetic, there should be negative angles, right? Well, as counter intuitive as it may seem at first sight, but we do use negative angles in Euclidean geometry and if you have solved Olympiad geometry problems before, then the concept of negative angles, a.k.a the "directed angles” is a really useful tool in dealing with configuration issues in Euclidean geometry.
In this video, I will be giving a comprehensive explanation on what is a directed angle and the four properties of directed angles.
*I noticed that there are some distortions of the video audio, sorry! I am not quite sure why it happened.
🔥Subscribe to 1Psi3Colour:
czcams.com/users/1Psi3Colour...
Video Chapters:
0:00 Our Conventional View of Angles
0:38 "Negative Angles"
1:05 The Problem with How We Define Angles
3:20 What Are Directed Angles?
6:06 Cyclic Quadrilaterals
7:25 Angle Addition Postulate
8:09 The Sum of Interior Angles of a Polygon
9:04 Collinearity Condition
10:24 Outro + Subscribe!
💥Check out these videos:
The integral everyone should know: • The MOST Influential I...
A deceivingly easy Putnam problem!: • Is This THE EASIEST Pr...
15 Minutes to Solve the First IMO 1959 Day 1 -- Can YOU?: • 15 Minutes to Solve th...
👉Check out these playlists:
Math Olympiad Problems from Different Countries:
• Math Olympiad Problems...
Math Shorts: • Math Shorts
Functional Equations:
• Functional Equations
👉Suggest a problem: forms.gle/hTibrUKz7QNyqoC48

[@NaN_000]

i didn't know about directed angle now i understand about it.
Thanks ! 👍

[@1psi3colourmath]

Great! Happy to help.

[@danieldandi2896]

In 7:20 why DAC=-CBD how you determine the - minus how to determine the clock or anticlockwise