Question

The perimeter of a square is $36cm$. Find the length of its diagonal.

Answer 1

Let $a$ be the edge of square.

Therefore,

Perimeter of square $=4a=36cm\left(\text{Given}\right)$

$\Rightarrow a=\frac{36}{4}=9cm$

As we know that,

Diagonal of a square $\left(d\right)=\sqrt{2}a$

$\therefore d=\sqrt{2}\times 9$

$\Rightarrow d=9\sqrt{2}cm\approx 12.73cm$