MathDB
equal angles wanted, mixtilinear excircle related

Source: 2014 All-Ukrainian Correspondence MO of magazine ''In the World of Mathematics'', grades 5-12 p12

April 27, 2021
geometrymixtilinearmixtilinear excircleequal anglesUkraine Correspondence

Problem Statement

Let ω\omega be the circumscribed circle of triangle ABCABC, and let ω′\omega' 'be the circle tangent to the side BCBC and the extensions of the sides ABAB and ACAC. The common tangents to the circles ω\omega and ω′\omega' intersect the line BCBC at points DD and EE. Prove that ∠BAD=∠CAE\angle BAD = \angle CAE.
Back to ProblemsView on AoPS