2020 IGO Elementary P2
Source: 7th Iranian Geometry Olympiad (Elementary) P2
November 4, 2020
geometryparallelogramangle bisector
Problem Statement
A parallelogram is given (). Points and are chosen on the line such that is the angle bisector of both angles and . The line intersects and at and , respectively. Prove that the line passes through the midpoint of .
Proposed by Mahdi Etesamifard