The correct option is: (D) AC2 + BD2
Explanation:
Let the length of sides of rhombus be x, length of OC be x1 and length of OD be y1. Then AB2 + BC2 + CD2 + DA2 = 4x2
Since, AC and DB bisect each other at O.
. .. AC = 2x1 and BD = 2y1
ln ΔAOD, ΔDOC, ΔAOB, ΔBOC