MathDB
an altitude of an acute triangle

Source: All-Russian 2007

May 4, 2007
geometrycircumcircleAsymptotepower of a pointradical axisperpendicular bisectorgeometry proposed

Problem Statement

Let ABCABC be an acute triangle. The points MM and NN are midpoints of ABAB and BCBC respectively, and BHBH is an altitude of ABCABC. The circumcircles of AHNAHN and CHMCHM meet in PP where PHP\ne H. Prove that PHPH passes through the midpoint of MNMN. V. Filimonov