MathDB
Medial line of a triangle

Source: Sharygin 2019 Finals Day 2 Grade 9 P3

July 31, 2019

Problem Statement

Let the incircle ω\omega of ABC\triangle ABC touch ACAC and ABAB at points EE and FF respectively. Points XX , YY of ω\omega are such that BXC=BYC=90\angle BXC=\angle BYC=90^{\circ} . Prove that EFEF and XYXY meet on the medial line of ABCABC .