Prism

Prisms are  polyhedron formed by two equal parallel regular polygon, end faces connected by side faces which are either rectangles or parallelograms.
Different types of prisms are shown in figure 2

Figure 2. Various types of prisms generally encountered in engineering applications

Some definitions regarding prisms

Base and lateral faces.  When the prism is placed vertically on one of its end faces, the end face on which the prism rests is called the base.  The vertical side faces are the lateral faces, as shown in Figure 3.

Figure 3. Shows the base and lateral face of a prism.

Base edge/Shorter edge:   These are the sides of the end faces, as shown in figure 4. 

     

 

Figure 4. showing the base edge or shorter edge of a pentagonal prism.