MathDB
Equal segment wanted

Source: 2022 Thailand MO Day 1 P1

June 15, 2022
geometry

Problem Statement

Let BCBC be a chord of a circle Γ\Gamma and AA be a point inside Γ\Gamma such that BAC\angle BAC is acute. Outside ABC\triangle ABC, construct two isosceles triangles ACP\triangle ACP and ABR\triangle ABR such that ACP\angle ACP and ABR\angle ABR are right angles. Let lines BABA and CACA meet Γ\Gamma again at points EE and FF, respectively. Let lines EPEP and FRFR meet Γ\Gamma again at points XX and YY, respectively. Prove that BX=CYBX=CY.