Question

Use vectors to prove that the diagonals AC¯¯¯¯¯¯¯¯ and BD¯¯¯¯¯¯¯¯ of a parallelogram bisect each other (Figure 32). Hint: Observe that the midpoint of BD¯¯¯¯¯¯¯¯ is the terminal point of w+12(v−w).