Geometric Solids

Cylinders are similar to prisms in that they have two congruent and parallel bases. However, the base of all cylinders are circles - not polygons.  Similar to prisms, there are right cylinders and oblique cylinders.  The drawing on the left is a right cylinder and the one on the right is an oblique cylinder.

cylinder 3-d

If you "unwrap" the middle section of a cylinder and lay it flat, it is a rectangle.  A cylinder's net is made up of a rectangle and two circles (the bases).