Question

The area of a circle is 16π cm2. What is the circle's circumference?

2π cm
4π cm
8π cm 1
6π cm

Answer 1

The formula for circumference is 2pi r

Answer 2

Answer:
`8\pi\ cm`

Explanation:

Area of circle is given by :-

`A=\pi r^2`, where r is the radius.

Given : The area of a circle is
`16\pi\ cm^2`

Then, we have

`\pi r^2=16\pi\\\\\Rightarrow\ r^2=16\\\\\Rightarrow\ r=\pm4`

Since r cannot be negative , so r=4 cm

The circumference of a circle is given by :-

`C=2\pi r\\\\\Rightarrow\ C=2\pi(4)=8\pi\ cm`

Hence, the circle's circumference =
`8\pi` cm