Sides of a Cylinder
What would the sides of a cylinder look like? A cylinder is similar to a soup can. Have you ever cut the label off of a soup can? When you lay it flat, it is a rectangle. (To visualize this easier, take a soup can out of your pantry and cut the label off!)
Here is a cylinder with radius r and height h. Although this is not a prism because the bases are circular, notice that it does have similar properties. It has two bases that are the same size and shape (circles) and are parallel to each other.
 |
Cylinder |
When the sides of this cylinder are laid out flat, it looks like this.
 |
Sides of the cylinder laid out flat |
Notice that there are two red circles (top and bottom), with radii r, and the curved surface (blue rectangle) with height h and width equal to the circumference of the circle, 2πr.
