Question

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

Answer 1

First, find the radius

2
`\pi`r=circumference
r=18
`\pi` cm
-------------
2
`\pi`
r=9 cm

Now, we can just use the circle area formula to solve


`\pi`
`r^(2)`
=
`\pi`
`9^(2)`
=81
`\pi`
=254.469 cm^2