Question

What is the volume of a sphere with a diameter of 18cm? Round the answer to the nearest whole number.

Answer 1

The volume of a sphere is givne by : 4/3(pi)(r)^3, in this case we are given the diameter, which we know is twice the radius, so by cutting the diameter in half we get the radius as being 9. Just plug r=9 into the formula

Answer 2

Here is a great document with plenty of volumes & surface area formulas with nice illustrations and color-coding. :)

(It's a PDF)
http://teachers.sduhsd.net/dspragg/documents/CheatSheetKey.pdf