Question

The perimeter of a rectangle is $42\mathrm{cm}$ . If its length is $13\mathrm{cm}$ then its area is ________${\mathrm{cm}}^2$

Answer 1

Length of the rectangle = $13cm$

Let breadth of the rectangle be $b$

Perimeter of rectangle =$42cm$

$2\times (length+breadth)=42$

$\Rightarrow 2\times (13+b)=42$

$\Rightarrow 13+b=\frac{42}{2}$

$\Rightarrow 13+b=21$

$\Rightarrow b=21-13$

$\Rightarrow b=8$

Now, breadth of rectangle =$8cm$

$\mathrm{Area}\mathrm{of}\mathrm{rectangle}=\mathrm{length}\times \mathrm{breadth}$

Now, Area of rectangle =$13\times 8=104c{m}^2$