Question

What is the area of a circle that has a circumference of 42 inches

Answer 1

The formula for the circumference of a circle is
`2 \pi r = C`. This means by setting this formula to 42 and solving for r, we can find the radius.


`2 \pi r = 42`

Divide by 2 on both sides.

`\pi r = 21`

Divide by
`\pi` on both sides.

`r = 6.68`

We can then use this value to compute the area, the formula of which is
`\pi r^2 = A`.


`\pi 6.68^2 = A`

Square 6.68.

`\pi 44.62 = A`

Multiply by pi.

`140.19 = A`

Therefore the area is 140.19
`in^2`.

Answer 2

Hello!
The formula for circumference is 2πR . (R - circle's radius)

π ≈ 3.1415
Equaling 2πR with 42 you'll have :

2*3.1415*R = 42

6.283*R = 42 (divide by 6.283)
R = 42/6.283

R ≈ 6.68 inches
The area is πR² , so it will be 6.68² * π = 44.65 *3.1415 ≈ 140.20 inches

Have a nice day !