Question

The circumference of a circle is 217 cm. What is the area, in square centimeters?

Express your answer in terms of TT.

Answer 1

A ≈ 1192.7727
`\pi`

Explanation:

To find:

• Find area A of a circle if circumference C = 217.

⇒ A = ?

⇒ C = 217

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STEP 1: find radius
`r`

To find radius
`r` use formula:

`C=2*r*\pi`

After substituting
`C=217` we have:

`217=2*r*\pi \\r=(217)/(2\pi )`

`r` ≈
`34.5365`

STEP 2: find area
`A`

To find area
`A` use formula:

`A=r^(2) *\pi`

After substituting
`r=34.5365` we have:

`A=34.5365^(2) *\pi \\A=1192.7727\pi`

Answer 2

Explanation:

You need to find r before you can find the area. You have the circumference so that will give you r.

When you have r, the Area formula is A = pi r^2

Find r from the circumference

C = 2 * pi * r Divide by 2 * pi

C/ * 2pi = 2*pi * r / 2pi Combine

C/2* pi = r

C = 217

C/2* pi = r

108.5 / pi = r

Find the Area

r = 108.5 / pi

Area = pi * r^2

Area = pi * 108.5^2 / pi^2

Area = 11772.25/ pi