Math: Geometry Problem 1007:
Hexagon, Midpoint, Triangle, Median, Centroid,
Concurrency. Level: School, College.
The figure shows a hexagon ABCDEFG.
M_{1}, M_{2}, M_{3}, M_{4}, M_{5},
and M_{6}, are the midpoints of sides. Prove that the medians of
triangles M_{1}M_{3}M_{5} and M_{2}M_{4}M_{6} are concurrent at O.
