MathDB
2003 KJMO P3

Source: 2003 Korea Junior Math Olympiad

June 29, 2024
geometryratiocircle

Problem Statement

Consider a triangle ABCABC, inscribed in OO and A<B\angle A < \angle B. Some point PP outside the circle satisfies A=PBA=180PCB\angle A=\angle PBA =180^{\circ}- \angle PCB Let DD be the intersection of line PBPB and OO(different from BB), and QQ the intersection of the tangent line of OO passing through AA and line CDCD. Show that CQ:AB=AQ2:AD2CQ : AB=AQ^2:AD^2.