MathDB
collinearity wanted, tangents to circumcircle related

Source: 2010 Moldova JBMO TST 1.3

July 12, 2020
geometrycircumcircleTangentscollinear

Problem Statement

The tangent to the circle circumscribed to the triangle ABCABC, taken through the vertex AA, intersects the line BCBC at the point PP, and the tangents to the same circle, taken through BB and CC, intersect the lines ACAC and ABAB, respectively at the points QQ and RR. Prove that the points P,QP, Q ¸ and RR are collinear.