Question

The circumference of a circle is 18TT inches. Which choice represents the exact area. of the circle? A:
`81\pi \: {inches}^(2)` B:
`324\pi \: {inches}^(2)`C:
`254.34 \: {inches}^(2)`D:
`1017.36 \: {inches}^(2)`

Answer 1

the circumference of the circle is,

2 x pi x r = 18 x pi

r = 18/2

r = 9

so the radius of the circle is 9

we know that the area of the circle is,

`A=\pi* r^2`

put the value r = 9

`\begin{gathered} A=\pi*9^2 \\ A=81*\pi \end{gathered}`

the area of the circle is 81 pi

thus the answer is option A