The Midpoints of Two Cevians
A cevian is a line drawn from a vertex of a triangle to the opposite side.[more]
Let ABC be a triangle and let M and N be the midpoints of the cevians BB' and CC'. Then the area of the quadrilateral BC'B'C is 4 times the area of AMN.[less]
The statement of the theorem is in Problem 90. Quadrilateral and Triangle Areas, Midpoints.