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3 lines concurrent with 1 circle

Source: 2021 Irish Mathematical Olympiad P8

May 30, 2021
concurrencyconcurrentgeometry

Problem Statement

A point CC lies on a line segment ABAB between AA and BB and circles are drawn having ACAC and CBCB as diameters. A common tangent to both circles touches the circle with ACAC as diameter at PCP \ne C and the circle with CBCB as diameter at QCQ \ne C. Prove that AP,BQAP, BQ and the common tangent to both circles at CC all meet at a single point which lies on the circumference of the circle with ABAB as diameter.