AC _|_ OQ wanted, 2 circles, tangent related
Source: 2006 VMEO III Seniors 12.1 Vietnamese Mathematics e - Olympiad https://artofproblemsolving.com/community/c2463155_vmeo_iii
September 17, 2021
perpendiculargeometry
Problem Statement
Given a circle and a point outside that circle. is a point running on the circle . The circle with center and diameter intersects circle again at . The tangent of at intersects at . The line through perpendicular to intersects at . intersects further at . intersects at . Prove that is perpendicular to .