IMO 2017 Shortlist G4
In triangle ABC, let ω be the ex ir le opposite A. Let D, E, and F be the points where ω is tangent to lines BC, CA, and...
Category: Geometry
Problem
In triangle ABC, let ω be the ex ir le opposite A. Let D, E, and F be the points where ω is tangent to lines BC, CA, and AB, respe tively. The ir le AEF interse ts line BC at P and Q. Let M be the midpoint of AD. Prove that the ir le MPQ is tangent to ω. (Denmark)