Add a link to figure on angle bisector

[stackgl]

Add a link to figure on angle bisector

[mikolalysenko]

Also this: http://en.wikipedia.org/wiki/Angle_bisector_theorem

[mikolalysenko]

I added some ascii art to help explain the theorem, and a bit more info. Hope they can figure it out.

[julescarbon]

This hint was not helpful for me either, seeing the angle bisector theorem was confusing and made me think about square roots and length(), rather than of addition and normalize().

I know what angle bisection is. But the ascii art made me think about triangles, rather than parallelograms. When I drew a parallelogram the solution made more sense, but still seemed like a leap especially for the third exercise.