MathDB
Geometry problem

Source: Moldova TST 2018

April 6, 2018
geometry

Problem Statement

Let Ω\Omega be the circumcincle of the quadrilateral ABCDABCD , and EE the intersection point of the diagonals ACAC and BDBD . A line passing through EE intersects ABAB and BCBC in points PP and QQ . A circle ,that is passing through point DD , is tangent to the line PQPQ in point EE and intersects Ω\Omega in point RR , different from DD . Prove that the points B,P,Q,B,P,Q, and RR are concyclic .