Use the given information to complete the proof of the following theorem If opposite sides of a quadrilateral are congruent then it is a parallelogram By definition a parallelogram is a quadrilateral in which both pairs of opposite sides are parallel Use this definition in your proof R S Given QR ST 3 4 1 QR ST 5 1 2 QT RS 6 2 7 4 3 Statement 40 40 41 40 4 2 40 QR QT RS Prove QRST is a parallelogram 8 QT II 9 QRST is a parallelogram Reason Given Given Reflexive Property Reason CPCTC Property CPCTC Property Reason Reason Reason