What is the exact area of a circle with the circumference of 18 pi centimeters

Given:
Circumference = 18 cm
pi = 3.14

Circumference of a circle = 2πr
Area of a circle = πr²

We need to get the radius of the circle from the circumference formula to get the area of the circle.

18 cm = 2 * 3.14 * r
18 cm = 6.28 * r
18 cm / 6.28 = r
2.87 cm = r

Area of a circle = 3.14 * (2.87cm)²
                          = 3.14 * 8.24 cm²
Area of a circle = 25.87 cm²

Area=pi times r^2
circunference=2pi times r

circunference=18pi
18pi=2pi times r
divide both sides by 2
9pi=pi times r
divide both sides by pi
9=r

subsitute
area=pi times r^2
area=pi times 9^2
area=pi times 81
area=81pi

answer is area=81pi cm^2