MathDB
Czech-Polish-Slovak Match 2016

Source: Czech-Polish-Slovak Match 2016,P3,day 2

July 12, 2016
geometry proposedgeometrycircumcircleCentroid

Problem Statement

Let ABCABC be an acute-angled triangle with AB<ACAB < AC. Tangent to its circumcircle Ω\Omega at AA intersects the line BCBC at DD. Let GG be the centroid of ABC\triangle ABC and let AGAG meet Ω\Omega again at HAH \neq A. Suppose the line DGDG intersects the lines ABAB and ACAC at EE and FF, respectively. Prove that EHG=GHF\angle EHG = \angle GHF.(Slovakia)