MathDB
tangent from $A$ to the circle meets the line $BC$ at point

Source: JBMO 2005, Problem 2

October 29, 2005
geometrypower of a pointradical axisgeometry proposed

Problem Statement

Let ABCABC be an acute-angled triangle inscribed in a circle kk. It is given that the tangent from AA to the circle meets the line BCBC at point PP. Let MM be the midpoint of the line segment APAP and RR be the second intersection point of the circle kk with the line BMBM. The line PRPR meets again the circle kk at point SS different from RR. Prove that the lines APAP and CSCS are parallel.