Question

The circumference of a circle is 123.2 cm. Taking $\pi =\frac{22}{7}$, calculate the area of the circle in $c{m}^2$, correct to the nearest $c{m}^2$ is

• A. $196c{m}^2$
• B. $1207c{m}^2$
• C. $2414c{m}^2$
• D. $2207c{m}^2$

Answer 1

The correct option is B $1207c{m}^2$

$Given-thecircumferenceCofacircle=r=123.2cm.Tofindout-theareaofthecircle=?$

$Solution-ThecircumferenceCofthecircle=2\pi r$

$\Rightarrow r=\frac{C}{2\pi }=\frac{123.2}{2\times \frac{22}{7}}cm=\frac{123.2\times 7}{2\times 22}cm=19.6cm.Nowar.circle=\pi r^2=\frac{22}{7}\times {19.6}^2{cm}^2=1207{cm}^2.Ans-OptionB.$