Problem

Source: Iran Third Round 2013 - Geometry Exam - Problem 1

Tags: geometry, circumcircle, geometric transformation, homothety, geometry unsolved



Let $ABCDE$ be a pentagon inscribe in a circle $(O)$. Let $ BE \cap AD = T$. Suppose the parallel line with $CD$ which passes through $T$ which cut $AB,CE$ at $X,Y$. If $\omega$ be the circumcircle of triangle $AXY$ then prove that $\omega$ is tangent to $(O)$.