Question

The circumference of a circle, whose area is $24.64m^2$, is

• A. $14.64m$
• B. $16.36m$
• C. $17.60m$
• D. $18.40m$

Answer 1

The correct option is C $17.60m$

$\pi x^2=24.64$

$x^2=\frac{24.64}{22}\times 7$

$=\frac{2464\times 7}{100\times 22}=\frac{112\times 7}{100}$

$x^2=\frac{16\times 7\times 7}{100}\Rightarrow x=\frac{4\times 7}{10}=\frac{28}{10}$

Circumference = $2\pi r$

$=2\times \frac{22}{7}\times \frac{28}{10}$

$=17.6m$