Question

Mark the correct alternative in the following question:

If the diagonal of a square is $\sqrt{8}$ metre, then its area is

(a) 8 m² (b) 4 m² (c) 16 m² (d) 6 m²

Answer 1

$$\begin{gathered} \mathrm{We}\mathrm{have}, \\ \mathrm{length}\mathrm{of}\mathrm{the}\mathrm{diagonal}\mathrm{of}\mathrm{the}\mathrm{square}=\sqrt{8}\mathrm{m} \\ \mathrm{Now},\mathrm{the}\mathrm{area}\mathrm{of}\mathrm{the}\mathrm{square}=\frac{1}{2}\times \mathrm{diagonal}\times \mathrm{diagonal} \\ =\frac{1}{2}\times \sqrt{8}\times \sqrt{8} \\ =\frac{8}{2} \\ =4{\mathrm{m}}^2 \end{gathered}$$

Hence, the correct alternative is option (b).