MathDB

2011.2

Part of Champions Tournament Seniors - geometry

Problems(1)

<AEF = 90^o if AB=AC, PQ// AB, F circumcener of PQC

Source: Champions Tournament (Ukraine) - Турнір чемпіонів - 2011 Seniors p2

5/21/2022
Let ABCABC be an isosceles triangle in which AB=ACAB = AC. On its sides BCBC and ACAC respectively are marked points PP and QQ so that PQ∥ABPQ\parallel AB. Let FF be the center of the circle circumscribed about the triangle PQCPQC, and EE the midpoint of the segment BQBQ. Prove that ∠AEF=90o\angle AEF = 90^o .
geometryright angleisoscelesChampions Tournament