cylinder, cone and sphere – three types of space figures that are not polyhedrons. – These figures have curved surfaces, not flat faces. – A cylinder is similar to a prism, but its two bases are circles, not polygons. Also, the sides of a cylinder are curved, not flat. – A cone has one circular base and a vertex that is not on the base. – The sphere is a space figure having all its points an equal distance from the center point.