Tuesday, October 19, 2010

How to find vertices, edges and faces of a prism given the sides or base?

1) To find the number of vertices, edges and faces of any prism given the number of sides (or) base, use this formula:

a) vertices of a prism = 2n
b) edges of a prism = 3n
c) faces of a prism = n + 2
where n is the number of sides of a prism

Examples:
Find the number of vertices, edges and faces of a hexagonal prism.

We know that a hexagon has 6 sides (n), therefore
vertices = 2n ==> 2 * 6 = 12
edges = 3n ==> 3 * 6 = 18
faces = n + 2 ==> 6 + 2 = 8