Question

The diagonals of a rhombus are $12$ cm and $16$ cm. Find its perimeter.

Answer 1

If the length of diagonals of rhombus be a and b. Then, length of side is:
$l^2=\frac{1}{4}(a^2+b^2)$
$l^2=\frac{1}{4}({12}^2+{16}^2)$
$l^2=\frac{1}{4}\left(400\right)$
$l=10cm$
Perimeter of rhombus $=4l=$ $4\times 10$ $=40$ cm