As the 2 quadrilaterals are congruent the sides of one quadrilateral are equal to the corresponding sides of the other quadrilateral Hence, AB = PQ RQ = BC AD = PS DC = RS Since terms for both AB and PQ are given we can equate the terms and find m 5m -9 = m + 11 5m -m = 11 + 9 4m = 20 m = 5 Correct answer is D , 5