In triangle , the altitude passes through midpoint of the median . Prove that in the triangle also one of the altitudes passes through the midpoint of one of the medians.
RU-ORAL-GEOMETRY 2015
Moscow Oral Geometry Olympiad 2015.
Other problems
The square and the equilateral triangle are located as shown in the figure. Find the angle .

In triangle , points , and are marked on sides , and respectively, so that , , . After that, they erased everything except points and . Reconstruct the triangle (no study required).