00:01
We need to find the radius given the following information for a, b, and c.
00:05
So our formula we're going to use for all of the circumference and is equal to 2 pi -r since we're looking for our radius.
00:19
C is equal to 2 -py -r.
00:22
So what we're given is c.
00:24
So in this case, we have 56 pi equals 2 -pr.
00:30
Since you have pi on both sides, the pies cancel out and we're left with 56 is equal to 2r.
00:35
We divide both sides by two, and 56 divided by two is 28.
00:42
So our r for our first one is 28 units long.
00:46
For letter b, we replace c with 314.
00:51
Then we have equals 2 pi r.
00:55
There's not pies on both sides, so we're going to have to leave the pie there and divide by 2 pi.
01:03
So our pi, 2 pi gets canceled out, so using our calculator 314.
01:07
Divided by 2 pi.
01:11
So they want us to round to the nearest hundredth.
01:14
So that's three decimal places.
01:16
Two decimal places, i'm sorry...