equilateral given and wanted, IMO TST problem
Source: Dutch IMO TST2 2015 p3
August 5, 2019
geometryEquilateralEquilateral Triangle
Problem Statement
An equilateral triangle is given. On the line through parallel to there is a point , such that and are on the same side of the line . The perpendicular bisector of intersects the line in . Prove that triangle is equilateral.