Arc Midpoints, Incenters, and Excenters

Explanations 2

• A lemma (or a few?) regarding the angle bisectors Important: It is assumed that the reader has understood circle basics (angle chasing in a cyclic quadrilateral), the circumcirc…

  By Yong See Foo, Expii Team, Alex Federspiel, Moor Xu

• The angle bisectors of a triangle meet in the incenter, and here is an easy proof of this fact: △ABC\triangle ABC△ABC has incenter III.Draw the perpendiculars from III to sides …

  By Darren Huang