BC^2 = CD \cdot CE wanted, trapezoid with perpendicular diagonals given,
Source: ITAMO 1998 p4
January 25, 2020
geometrytrapezoidperpendicular
Problem Statement
Let be a trapezoid with the longer base such that its diagonals and are perpendicular. Let be the circumcenter of the triangle and be the intersection of the lines and . Prove that .