Question

Choose the correct alternative answer for the following question.

The ratio of circumference and area of a circle is 2:7. Find its circumference.

विकल्प

• \[14\pi\]

   

•   \[\frac{7}{\pi}\]

   

• 7\[\pi\]

• \[\frac{14}{\pi}\]

   

Answer 1

 Let r be the radius of the circle.
Circumference of the circle : Area of the circle = 2 : 7 

\[\Rightarrow \frac{2\pi r}{\pi r^2} = \frac{2}{7}\]
\[ \Rightarrow \frac{1}{r} = \frac{1}{7}\]
\[ \Rightarrow r = 7\]

∴ Circumference of the circle =  \[2\pi r = 2\pi \times 7 = 14\pi\]