Note on terminology - cones and cylinders

In modern mathematics the terms "cone" and "cylinder" have very general meanings: The base of a cone or a cylinder can be any plane figure. That's the way I have been using these terms in class.

Traditionally the terms cone and cylinder were used only when the base is a circle. This usage is still predominant in K-12 math textbooks. Special terms are used when the base is a polygon. A cone with polygonal base is called a pyramid, and a cylinder with polygonal base is called a prism.

So in homework 2, the traditional terminology for an infinite right square cylinder would be an infinite right square prism. The adjective "right" indicates that the axis of the cylinder or prism is perpendicular to the plane of the base.