MathDB
cyclic hexagon wanted with opposite sides // and not equal

Source: 2023 Croatia MO p3 HMO https://artofproblemsolving.com/community/c1251476_croatia_mo_hmo___geometry

May 5, 2024
geometryhexagonCyclic

Problem Statement

A convex hexagon ABCDEFABCDEF is given, with each two opposite sides of different lengths and parallel (ABDEAB \parallel DE, BCEFBC \parallel EF and CDFACD \parallel FA). If AE=BD|AE| = |BD| and BF=CE|BF| = |CE|, prove that the hexagon ABCDEFABCDEF is cyclic.