2019 IGO Intermediate P5
Source: 6th Iranian Geometry Olympiad (Intermediate) P5
September 20, 2019
IGOIrangeometry
Problem Statement
Let be a triangle with . Points and are the foot of angle bisectors of vertices and respectively. Points and are considered such that quadrilaterals and are parallelograms. Prove that . (Consider the angle that does not contain side of the triangle.)Proposed by Alireza Dadgarnia