Question

The perimeter of square and circumference of Circle are equal, the area of square is $121m^2$, then the area of circle is

• A. $7\pi m^2$
• B. $14\pi m^2$
• C. $21\pi m^2$
• D. $49\pi m^2$

Answer 1

The correct option is D $49\pi m^2$

• Area of square $=(side{)}^2$

$(side{)}^2=121=(11{)}^2$
$\Rightarrow$ Side of square $=11$m
$\therefore$ Perimeter $=11\times 4=44$m
Perimeter of square =Circumference of circle
$C=2\pi r$
$44=2\times \frac{22}{7}r$
$\Rightarrow r=\frac{44\times 7}{44}=7$m
Area of circle $=\pi r^2=\pi \times (7{)}^2=49\pi m^2$