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Prove that the lines $BP$ and $CQ$ are perpendicular.

Source: Moldova TST 2022

April 1, 2022
geometry

Problem Statement

Let AA be a point outside of the circle Ω\Omega. Tangents from AA touch Ω\Omega in points BB and CC. Point CC, collinear with AA and PP, is between AA and PP, such that the circumcircle of triangle ABPABP intersects Ω\Omega again in point EE. Point QQ is on the segment BPBP, such that PEQ=2APB\angle PEQ=2 \cdot \angle APB. Prove that the lines BPBP and CQCQ are perpendicular.