A steel wire when bent in the form of a square

Solution:

Let a cm be the side of square. Then area of square is

$a^{2}=121 \mathrm{~cm}^{2}$

$a=\sqrt{121 \mathrm{~cm}^{2}}$

$a=11 \mathrm{~cm}$

We have,

length of wire $=$ perimeter of square

$=4 a \mathrm{~cm}$

$=4 \times 11 \mathrm{~cm}$

 

$=44 \mathrm{~cm}$

Let the radius of circle be r cm. Then,

circumference of circle $=$ length of wire

$2 \pi r=44 \mathrm{~cm}$

$2 \times \frac{22}{7} \times r=44 \mathrm{~cm}$

$r=7 \mathrm{~cm}$

Now, we will calculate area of circle.

Area of circle $=\pi r^{2} \mathrm{~cm}^{2}$

$=\frac{22}{7} \times 7 \times 7 \mathrm{~cm}^{2}$

 

$=154 \mathrm{~cm}^{2}$