MathDB
2014 China Second Round Olympiad Second Part Problem 2

Source: 2014 China Second Round Olympiad

August 4, 2015
geometrycircumcircle

Problem Statement

Let ABCABC be an acute triangle such that BAC60\angle BAC \neq 60^\circ. Let D,ED,E be points such that BD,CEBD,CE are tangent to the circumcircle of ABCABC and BD=CE=BCBD=CE=BC (AA is on one side of line BCBC and D,ED,E are on the other side). Let F,GF,G be intersections of line DEDE and lines AB,ACAB,AC. Let MM be intersection of CFCF and BDBD, and NN be intersection of CECE and BGBG. Prove that AM=ANAM=AN.