Right triangles
Source: IMO LongList 1982 - P54
September 10, 2010
geometryTriangleright trianglesimilar trianglesperpendicularIMO ShortlistIMO Longlist
Problem Statement
The right triangles and are similar and have opposite orientation. The right angles are at and , and we also have . Let be the point of intersection of the lines and . Prove that if the lines and exist, they are perpendicular.