Question

The perimeter of a rectangle having area equal to $144c{m}^2$ and sides in the ratio $4:9$ is ______ .

Answer 1

Let $l=9x$ and $b=4x$

Area of rectangle $=l\times b$

$\Rightarrow 9x\times 4x=144$

$\Rightarrow 36x^2=144$

$\Rightarrow x^2=4$

$\therefore x=2$

So, $l=18cm$ and $b=8cm$

Perimeter of rectangle $=2\times (l+b)$

$=2(18+8)$

$=2\times 26$

$=52cm$