tangent lines at given youchpoints wanted, incenter, circumcircle related
Source: 2014 Croatia MO p7
August 5, 2020
geometryincentercircumcircletangent
Problem Statement
Let point be the center of the inscribed circle of an acute-angled triangle . Rays and intersect the circumcircle of triangle at points and respectively. The segments and intersect at point , the line through point parallel to the line intersects the circle at point , and the lines and intersect at point . Prove that the lines and touch the circumcircle of the triangle at the points and respectively.