Question

The area of a square is 200 cm². The length of its diagonal is

(a) 10 cm
(b) 20 cm
(c) $10\sqrt{2}$ cm
(d) 14.1 cm

Answer 1

(b) 20 cm

Area of the square = $\left\{\frac{1}{2}\times {\left(D\mathrm{iagonal}\right)}^2\right\}$ sq. units.
Area of the square field = 200 cm²

Diagonal of a square = $\sqrt{2\times \mathrm{Area}\mathrm{of}\mathrm{the}\mathrm{square}}$
= $\left(\sqrt{2\times 200}\right)$ cm = $\left(\sqrt{400}\right)$ cm = 20 cm
∴ Length of the diagonal of the square = 20 cm