MathDB
A, P, Q are collinear

Source: Junior Olympiad of Malaysia Shortlist 2015 G3

July 17, 2015
geometry

Problem Statement

Let ABC ABC a triangle. Let DD on ABAB and EE on ACAC such that DEBCDE||BC. Let line DEDE intersect circumcircle of ABCABC at two distinct points FF and GG so that line segments BFBF and CGCG intersect at P. Let circumcircle of GDPGDP and FEPFEP intersect again at QQ. Prove that A,P,QA, P, Q are collinear.