Please give the original wording of the problem.
There are several things wrong with your version.
The pool is only ten feet long? . . . Is it a child's wading pool?If you were buying a pool and it says the size is 10FT. X 30",
what is the diameter of the pool and the circumference?
The pool is thirty inches wide? . . . That's the width of a door!
Only circles have diameters and cirumferences.