I am not sure what this problem is trying to get me to do:

Question

Midline Theorem. Draw a triangle ABC, and let M and N be the midpoints of sides AB and AC, respectively. Express vector/line BC and vector/line MN in terms of u = vector AB and v = vector AC.

Answer 1

BC = AB - A C = u - v

MN = 1/2BC = 1/2(u - v)