Question

A steel wire bent in the form of a square of area $121c{m}^2$. If the same wire is bent in the form of a circle, then the area of the circle is

• A. $130c{m}^2$
• B. $136c{m}^2$
• C. $154c{m}^2$
• D. $168c{m}^2$

Answer 1

The correct option is C $154c{m}^2$

If it's a square, then each side is $=\sqrt{121}=11cm$

Therefore, the length of the wire is $11\times 4=44cm$ which is the circumference.

The circumference of circle $=2\pi \times r$

$44=2\pi \times r$

$22=\pi \times r$

$22=\frac{22}{7}\times r$

Hence, $r=7cm$

$Area=\pi \times r^2$

$Area=\frac{22}{7}\times 7^2=154c{m}^2$