# Math Help - Circumference of a Circle

1. ## Circumference of a Circle

Question :- Find the circumference of a circle known that area of the circle is 153.86 ?

2. ## Re: Circumference of a Circle

The circumference of a circle is $2\pi r$

The area of a circle is $\pi r^2$

You know that the area of the circle is equal to 153.86.

Using the above formula for the area a circle, you should be able to find the radius (r), and plug it into the formula for the circumference of a circle