MathDB
Three concurrent chords in a circle

Source: Kosovo TST 2024 P2

March 19, 2024
TSTgeometrycircleChordsconcurrent linesTangents

Problem Statement

Let ω\omega be a circle and let AA be a point lying outside of ω\omega. The tangents from AA to ω\omega touch ω\omega at points BB and CC. Let MM be the midpoint of BCBC and let DD a point on the side BCBC different from MM. The circle with diameter ADAD intersects ω\omega at points XX and YY and the circumcircle of ABC\bigtriangleup ABC again at EE. Prove that ADAD, EMEM, and XYXY are concurrent.