Question

The circumference of a circle is 3 pi miles. What is the diameter?

Answer 1

Diameter is 3

Explanation:

C=2πr

3π = 2πr

3π / 2π = r (Divide each side by 2π)

3/2 = r (Simplify π)

3/2 *2 = d (d = 2r)

d = 6/2 = 3

Answer 2

3 miles

Explanation:

The circumference of a circle can be found using:

c=
`\pi d`

We know the circumference is
`3\pi`, so we can substitute that in for c

`3\pi`=
`\pi d`

We want to find the diameter. To do this, we need to get d by itself. It is being multiplied by pi. To undo this, divide both sides by pi. This will cancel pi, and leave d by itself.

`3\pi /\pi =\pi d/ \pi`

3=d

So, the diameter is 3 miles