Question

The area of a circle is 81 pi in2 what is the circumference in inches express ur answer in terms of pi

Answer 1

Circumference of circle = 18π inches

Explanation:

Given the following data;

Area of circle = 81π in²

To find the circumference;

First of all, we would find the radius of the circle using the area of circle formula.

Area of circle = πr²

Substituting into the formula, we have:

81π = πr²

Dividing both sides by π, we have;

81 = r²

Taking the square root of both sides, we have;

r = 9 inches

Now, to find the circumference of the circle;

Circumference of circle = 2πr

Circumference of circle = 2*π*9

Circumference of circle = 18π inches.