2001 Spanish Mathematical Olympiad, Problem 2
Source: Spanish Mathematical Olympiad 2001
June 5, 2017
geometrysimilar triangles
Problem Statement
Let be a point on the interior of triangle , such that the triangle satisfies . On each of the other sides of , build triangles and exteriorly, both similar to triangle satisfying: and
Prove that the point and are collinear or are the vertices of a parallelogram.