Question

You have a new pool and want to know its volume. The pool is 5 feet deep and has a radius of 7 feet. About how much water can the pool hold?

Answer 1

Vol = 769.7 cubic ft

Explanation:

"radius" is the distance from the center of a circle to the circle. So let's assume your pool is a circular pool with radius = 7ft and height = 5ft. It's a cylinder.

Volume of a cylinder:

Vol =

Base area•height

= pi•r^2 • h

= pi(7)^2•5

= pi•49•5

= pi • 245

= 245pi

Now, 245pi cubic ft is a perfectly good answer. But your teacher/text/class, may be asking for a decimal approximation.

If you use calculator pi (that's a lot of decimals) you get

Vol ~= 769.69 (to the hundredths place)

Vol ~= 769.7(to the tenths place)

If you were told to use 3.14 for pi

then you get

Vol ~= 769.3 cubic ft

But if you were told to convert units to gallons or liters there are more calculations (message, i can edit in these)