If the length of diagonal AC of a square ABCD is 5.2 cm, then the area of the square is :

Answer: Option D

Area of the square :
$$\begin{array}{rl}& =\left[\frac{1}{2}\times {\left(5.2\right)}^2\right]\text{ sq}\text{.cm}\\ & \text{ = }\left(\frac{1}{2}\times 27.04\right)\text{ sq}\text{.cm}\\ & =13.52\text{ sq}\text{.cm}\end{array}$$