00:01
Okay, so for this problem, you're looking for the perimeter of this figure here on the left.
00:05
So in order to calculate perimeter, remember you need to add up all of the sides.
00:10
So for us, the perimeter consists of a small arc in the middle, which is a semicircle that has a radius of three.
00:21
We have the big arc on the outside, which is a semicircle with radius of three plus that edge.
00:31
So that would be a radius of four.
00:34
And then we've got two kind of straight pieces that are both one inch a piece.
00:40
So if we add up all four of those things, we should get the perimeter of this figure.
00:46
Now, to find the length of an arc, or a semicircle, remember you have to do one -half pi times the diameter.
00:58
That would apply for this one as well.
01:00
1 1ā2 pi times the diameter.
01:05
And then the straight edges on the side are just 1 inch each.
01:09
There's not a formula for that.
01:12
So now we can plug in the information that we know.
01:16
So we have 1ā2...