MathDB
Bash geo

Source: BMO Shortlist 2022, G6 & Romanian TST 2022, Day 3 P2

May 13, 2023
geometry

Problem Statement

Let ABCABC be a triangle with AB<ACAB < AC and let DD{} be the other intersection point of the angle bisector of A\angle A with the circumcircle of the triangle ABCABC. Let EE{} and FF{} be points on the sides ABAB and ACAC respectively, such that AE=AFAE = AF and let PP{} be the point of intersection of ADAD and EFEF. Let MM{} be the midpoint of BCBC{}. Prove that AMAM and the circumcircles of the triangles AEFAEF and PMDPMD pass through a common point.