Three Subtriangles of a Triangle
A cevian is a line drawn from a vertex of a triangle to the opposite side.[more]
Let ABC be a triangle. Let BB' and CC' be cevians. Let M and N be the midpoints of BB' and CC' respectively. Let R and S be the points of intersection of AM and AN with C'B'. Then .[less]
The statement of the theorem is in Problem 89. Triangle area, Midpoints.