As shown in the figure, ▱ in ABCD, m, N, P and Q are the points on AB, BC, CD and Da respectively, and am = BN = CP = DQ

As shown in the figure, ▱ in ABCD, m, N, P and Q are the points on AB, BC, CD and Da respectively, and am = BN = CP = DQ


It is proved that: ∵ quadrilateral ABCD is a parallelogram, ∵ AB = CD, ad = BC, ∵ a = ∵ C, ∵ B = ∵ D. ∵ am = BN = CP = DQ, ∵ ab-am = cd-cp, ad-dq = bc-bn, that is BM = DP, AQ = CN. In △ AMQ and △ CPN, am = CP, ≌ a =