MathDB
Prove two lines are perpendicular

Source: XVII Sharygin Correspondence Round P2

March 2, 2021
geometry

Problem Statement

A perpendicular bisector to the side ACAC of triangle ABCABC meets BC,ABBC,AB at points A1A_1 and C1C_1 respectively. Points O,O1O,O_1 are the circumcenters of triangles ABCABC and A1BC1A_1BC_1 respectively. Prove that C1O1⊥AOC_1O_1\perp AO.
Back to ProblemsView on AoPS