Question

The circumference of a circle can be found using the formula C = 2 nr.

Answer 1

Radius = circumference/2(3.14)
OPTION 3

Answer 2

We know that the circumfrence of a circle equals pi times two.

So how can we rearrange this?

I will substitute pi with 3.14 to make it easier.

$C = 2 (3.14) r$ is the original equation.

To make the radius come first, we can the circumfrence by $2(3.14)$.

$r =\frac{c}{2(3.14) }$ would be the answer.

We can check that:

Suppose r=6

$C = 2(3.14)6\\6.28 (6)\\=37.68$

If the circumfrence is 37.68, we can plug it in to the formula we found.

$6 = \frac{37.68}{2(3.14)} \\6 = \frac{37.68}{6.28} \\6 = 6$

It's correct! The answer is the third one!