Question

The perimeter of a rectangle is $40m$. Its length is four meters less than five times its breadth. Find the area, the rectangle.

Answer 1

Let, breadth of rectangle is $x$, then $5x-4$ be the length of the rectangle.

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

$\Rightarrow 40=2(l+b)$

$\Rightarrow 40=2(5x-4+x)$

$\Rightarrow 40=12x-8$

$\Rightarrow 12x=40+8$

$\Rightarrow 12x=48$

$\Rightarrow x=\frac{48}{12}$

$\Rightarrow x=4$

Breadth $=4$ meters

Hence, length $=5\times 4-4=20-4=16m$

Therefore, area of rectangle $=lb=16\times 4=64m^2$