As shown in the figure, fold the four corners of rectangle ABCD inward to form a seamless quadrilateral efgh, eh = 12cm, EF = 16cm, then the length of side ad is () A. 12 cm B. 16 cm C. 20 cm D. 28 cm

As shown in the figure, fold the four corners of rectangle ABCD inward to form a seamless quadrilateral efgh, eh = 12cm, EF = 16cm, then the length of side ad is () A. 12 cm B. 16 cm C. 20 cm D. 28 cm

Let P and Q be the two points on the oblique line respectively, P and p be the point B folded in half, Eph be the right angle, △ AEH ≌ △ Peh, hea = ∠ Peh, similarly, PEF = ∠ bef, Peh + PEF = 90 degree, efgh be the rectangle, DHG ≌ △ BFE, HEF be the right triangle, BF = DH = PF, ≌ ah = HP, ≌ ad = HF, ∥ eh = 12cm, EF = 16cm, ∥ FH = Eh2 + ef2 = 122 + 162 = 20cm, FH = ad = 20cm C