2020 IGO Intermediate P2
Source: 7th Iranian Geometry Olympiad (Intermediate) P2
November 4, 2020
rectanglecircumcircleanglesTrianglegeometryIGO
Problem Statement
Let be an isosceles triangle () with its circumcenter . Point is the midpoint of the segment and point is the reflection of the point with respect to the side . Suppose that is a point so that is a rectangle. Prove that .Proposed by Ali Zamani