Read the section below and complete the following activity (adapted from Lesson 9.1). Proving Diagonals Bisect Each Other Theorem 3 If a quadrilateral is a parallelogram, then its diagonals bisect each other. The figure WXYZ is a parallelogram. WYXZ Below is the flow proof that the diagonals of a parallelogram bisect each other. Given: ABCD is a parallelogram. Prove: AE CE and BE DE D ABDC Definition of parallelogram ZABECDE Alternate Interior Angles Theorem ABCD is a parallelogram. Given ABDC Opposite sides of a parallelogram are congruent. ZBAEZDCE Alternate Interior Angles Theorem AABE ACDE ASA Triangle Congruence Theorem AECE and BEDE CPCTC