MathDB
geometry in a isosceles

Source: 2nd National Women´s Contest of Mexican Mathematics Olympiad 2023 , problem 1 teams

July 23, 2023
geometryisoscelesMexico

Problem Statement

Let △ABC\triangle ABC such that AB=ACAB=AC, DD and EE points on ABAB and BCBC, respectively, with DE∥ACDE\parallel AC. Let FF on line DEDE such that CADFCADF it´s a parallelogram. If OO is the circumcenter of △BDE\triangle BDE, prove that O,F,AO,F,A and DD lie on a circle.
Back to ProblemsView on AoPS