MathDB
Circles through A, tangent to DE

Source: Macedonian TST 2022, P4

May 21, 2022
geometry

Problem Statement

Given is an acute triangle ABCABC with AB<ACAB<AC with altitudes BDBD and CECE. Let the tangents to the circumcircle at BB and CC meet at YY. Let ω1\omega_1 be the circle through AA tangent to DEDE at EE; define ω2\omega_2 similarly, and let their intersection point be XX. Prove that A,X,YA, X, Y are colinear.
<spanclass=latexitalic>ProposedbyNikolaVelov</span><span class='latex-italic'>Proposed by Nikola Velov</span>