Problem

Source: 2021 Sharygin Geometry Olympiad Finals grade IX p5

Tags: Concyclic, Circumcenter, geometry



Let $O$ be the clrcumcenter of triangle $ABC$. Points $X$ and $Y$ on side $BC$ are such that $AX = BX$ and $AY = CY$. Prove that the circumcircle of triangle $AXY$ passes through the circumceuters of triangles $AOB$ and $AOC$.