The length of diagonal of a square whose area is 216 cm2 is?

18 cm 12\(\sqrt {3}\) cm 12 cm 16\(\sqrt {3}\) cm

12\(\sqrt {3}\) cm

Area of sqaure = (side)2 ⇒ 216 = (side)2 ⇒ side = 6\(\sqrt {6}\) cm diagonal of square = \(\sqrt {2}\) × side                             = \(\sqrt {2}\) × 6\(\sqrt {6}\)                           = 6\(\sqrt {12}\) = 12\(\sqrt {3}\) cm