Question

Circumference of a circle disc is $88\mathrm{cm}$. Its radius is -

• A. $8\mathrm{cm}$
• B. $11\mathrm{cm}$
• C. $14\mathrm{cm}$
• D. $44\mathrm{cm}$

Answer 1

The correct option is C

$14\mathrm{cm}$

Step 1: Write the formula for circumference in terms of radius.

A distance covered by traveling once around a circle is its perimeter, usually called its circumference.

$\mathrm{circumference}=2\mathrm{\pi r}$.

Where, $r$ is the radius of the circle and $\pi$ is a constant $\left(\pi =\frac{22}{7}\right)$.

Step 2: Apply the above relation and find the circle's radius.

$$\begin{gathered} 88=2\pi r \\ \Rightarrow 88=2\times \frac{22}{7}\times r \\ \Rightarrow r=88\times \frac{7}{22\times 2} \\ \Rightarrow r=14\mathrm{cm} \end{gathered}$$

Hence the correct answer is option (C).