Question

Given that the area of a circle is 49π, find the circumference of this circle.

Answer 1

The circumference of this circle is
`14\pi`

Explanation:

The area of a circle is calculated using the following formula:

`A = \pi r ^ 2`

Where A is the area of the circle and r is the radius.

For this case we know that the area of the circle is 49π.

So:

`49\pi = \pi r ^ 2`

Now we solve the equation for r

`\pi r ^ 2 = 49\pi\\r ^ 2 = 49\\r = 7`

Also, the circumference of a circle is calculated using the following formula:

`C = 2pi r`

Where r is the radius of the circle. We know that r = 7 so we can calculate the circumference:

`C = 2 \pi(7)\\\\C = 14\pi`