Circle Theorem-XVII : Intersecting Secant Lines | JEE | CBSE | ICSE

In this video, I have explained in details how to prove that for secant lines intersecting outside of a circle: PA x PB = PC x PD if P is the external point where the 2 secant lines intersect, AB is the intercept (chord) of the 1st secant line and CD is the intercept (chord) of the 2nd secant line.
The proof has been done using the properties of similar triangles.