geometry problem
Source: Netherlands TST for IMO 2017 day 3 problem 1
February 1, 2018
geometry
Problem Statement
A circle with diameter is given. The point lies in the interior of the circle, but not on . The line intersects in and . The tangent to at intersects the line through perpendicular to , at . The point lies on , and is such that is tangent to and .
Show that , and are collinear.