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equal angles wanted, circles, tangents, symmetric point given

Source: Ukrainian Geometry Olympiad 2020, IX p2, X p1, XI p1

April 27, 2020
geometryequal anglescirclestangentsymmetry

Problem Statement

Let Γ\Gamma be a circle and PP be a point outside, PAPA and PBPB be tangents to Γ\Gamma , A,BΓA, B \in \Gamma . Point KK is an arbitrary point on the segment ABAB. The circumscirbed circle of PKB\vartriangle PKB intersects Γ\Gamma for the second time at point TT, point PP' is symmetric to point PP wrt point AA. Prove that PBT=PKA\angle PBT = \angle P'KA.