As shown in the figure, in diamond ABCD, the diagonal lines AC and BD intersect at point O. if OA = 4 and ob = 3, the perimeter of diamond ABCD is () A. 5B. 12C. 16D. 20
In RT △ OAB, ab = oa2 + ob2 = 5, and the circumference of the diamond ABCD is 4 × 5 = 20