SAMO 2013 Senior Round 3 Problem 3 - Tangent to Circumcircle
Source:
September 17, 2013
geometrycircumcircle
Problem Statement
Let ABC be an acute-angled triangle and AD one of its altitudes (D on BC). The line through D parallel to AB is denoted by , and t is the tangent to the circumcircle of ABC at A. Finally, let E be the intersection of and t. Show that CE and t are perpendicular to each other.