Question

The sum of the circumference and diameter of a circle is $116cm$. Find its radius.

• A. $14$ cm
• B. $14$ m
• C. $24$ cm
• D. $1.4$ cm

Answer 1

The correct option is A $14$ cm

Let the radius be $r$cm.

The sum of the circumference and diameter of a circle is $116$cm.

Therefore, $2\pi r+2r=116$

$\Rightarrow 2r(1+\pi )=116$

$\Rightarrow r=\frac{116}{2(1+\pi )}$

$\Rightarrow \frac{58}{1+\pi }$

$\Rightarrow \frac{58}{1+\frac{22}{7}}$

$\Rightarrow \frac{58\times 7}{29}$

$=14$cm