00:01
Right here on this problem we have two circles with the same center.
00:04
You're looking for the area of the walkway, and the walkway is just this outer part right here.
00:11
That's the part that you're looking for the area of.
00:14
Now what we're going to do to find it is find the area of the big circle here, and then subtract off the area of that little circle.
00:21
So the area of the big one minus the area of the small one.
00:25
Now this inside one has a radius of 10, and the walkway is three feet.
00:31
So the walkway adds another three feet.
00:34
And so if you're looking at this big blue circle here, its radius is 13 because it includes the walkway and the inner circle.
00:43
So that big circle has a radius of 13.
00:47
And so its area is pi r squared, which is pi times 13 squared.
00:56
And when you type that in on a calculator, it's going to give you 530 .9.
01:01
So the area of the whole thing here is 530 .9...