Question

Henry knows that the circumference of a circle is 18Pi inches. What is the area of the circle?

36 pi inches squared
81 pi inches squared
162 pi inches squared
324 pi inches squared

Answer 1

81 pi inches squared (Option B)

Explanation:

C = 2 pi r

18 = two pi r

r = 9

Then use the radius to find the area of the circle which is 81 pi.

Answer 2

81π

Explanation:

Because the circumference is 18 pi the diameter is also 18 which means the radius is 9. This means that its area is 81 pi.