Border Around a Pool

[mathxyz]

A pool in the shape of a circle measures 10 feet across. One cubic yard of concrete is to be used to create a circular border of uniform width around the pool. If the border is to have a depth of 3 inches, how wide will the border be?

( 1 cubic yard = 27 cubic feet)

 

[Guest]

The volume of the concrete is 1 cubic yard, and the depth is 3 inches, so what is the area on top of it?

Let w = width of border

Now how do you find the area of the border in terms of w?

 

[mathxyz]

okay

I will have to set up the correct equation just like the garden question.
I hope I can take it from here.