Hands-on math!

Cone

A cone is a 3-dimensional (solid) figure that has a circle for a base and has a single vertex at the top, called the apex.

The volume of a cone with a circular base of radius r and height h is:
  • V = r2 h / 3
The surface area of a cone consists of 2 parts:
  • The circular base: Abase = r2
  • The sides:             Aside = r L
    where L is the length of the side, called the 'slant length'.
If you cut a cone along the side L and lay it out flat, it looks like this:
 When you cut up a solid figure and lay it out flat (like this), that is called a
geometry net
Now, here is a problem for you:
What is the volume of this cone?
Leave your answer in terms of π.


Volume = _______ π cu. in.