Question

If the area of a circle is $346.5c{m}^2$. Its circumference is

• A. $11cm$
• B. $66cm$
• C. $22cm$
• D. $44cm$

Answer 1

The correct option is B $66cm$

$\pi r^2=346.5c{m}^2$
$\frac{22}{7}{r}^2=346.5c{m}^2$
$r^2=346.5\times \frac{7}{22}=110.25$
$\Rightarrow r=10.5cm$
$C=2\pi r=2\times \frac{22}{7}\times 10.5=66cm.$