Geometric Inequality - South African Maths Olympiad
Source: SAMO Senior Round 3 2013 Problem 6
September 17, 2013
inequalitiesgeometrycircumcirclegeometry unsolved
Problem Statement
Let be an acute-angled triangle with , and let be the circumcentre and the foot of the altitude through . Furthermore, let and be the feet of the perpendiculars dropped from and respectively to (the extension of) . The line intersects the circumcircle of a second time at . Prove that .