Problem

Source: Sharygin 2010 Final 8.5

Tags: geometry, altitude, median, angle bisector



Let $AH$, $BL$ and $CM$ be an altitude, a bisectrix and a median in triangle $ABC$. It is known that lines $AH$ and $BL$ are an altitude and a bisectrix of triangle $HLM$. Prove that line $CM$ is a median of this triangle.