Three concurrent lines
Source: Baltic Way 2000 Problem 3
February 13, 2009
geometrycircumcircletrigonometrygeometry unsolved
Problem Statement
Given a triangle with \angle A \equal{} 90^{\circ} and . The points , , lie on the sides , , , respectively, in such a way that is a square. Prove that the line , the line and the line tangent at the point to the circumcircle of the triangle intersect in one point.