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Geometry in Taiwan TST

Source: 2024 Taiwan TST Round 1 Independent Study 2-G

March 7, 2024
geometry

Problem Statement

For the quadrilateral ABCDABCD, let ACAC and BDBD intersect at EE, ABAB and CDCD intersect at FF, and ADAD and BCBC intersect at GG. Additionally, let W,X,YW, X, Y, and ZZ be the points of symmetry to EE with respect to AB,BC,CD,AB, BC, CD, and DADA respectively. Prove that one of the intersection points of (FWY)\odot(FWY) and (GXZ)\odot(GXZ) lies on the line FGFG.
Proposed by chengbilly