posted by EKH .
quadrilateral A B C D on a graph. Point A is at ( -5, -1), Point B is at ( 6, 1), Point C is at (4, -3), Point D is at (-7, -5).
Prove the quadrilateral is a parallelogram by using Theorem 5-7; if the diagonals of a quadrilateral bisect each other, then it is a parallelogram. (Hint: Use the Midpoint formula.)
well, what are the diagonals?
AC and BD
midpoint of AC = (-1/2,-2)
midpoint of BD = (-1/2,-2)
Looks like the diagonals bisect each other.