Question

A circular wire of diameter $42cm$ is bent in the form of a rectangle whose sides are in the ratio $6:5$. The area of the rectangle is $(\pi =\frac{22}{7})$

• A. $540c{m}^2$
• B. $1080c{m}^2$
• C. $2160c{m}^2$
• D. $4320c{m}^2$

Answer 1

The correct option is B $1080c{m}^2$

Let length of rectangle $=6x$

Breadth of rectangle$=5x$

Perimeter of rectangle=Perimeter of circle

$\Rightarrow 2(6x+5x)=2\pi r=2\times \frac{22}{7}\times 21$

$\Rightarrow 22x=6\times 22\Rightarrow x=6$

$\therefore l=6\times 6=36cm,b=5\times 6=30cm$

Area of rectangle$=lb=36\times 30=1080c{m}^2$