prove that <BGE <= < AED / 2
Source: 2015 Sharygin Geometry Olympiad Correspondence Round P3
August 2, 2018
geometryisoscelessquare
Problem Statement
The side of a square is the base of an obtuse-angled isosceles triangle with vertex lying inside the square. Let be a diameter of the circumcircle of this triangle, and be a point on such that . Prove that angle is less than half of angle .