The Wedge

Man's Way of Helping Himself:
If an inclined plane is pushed underneath or within an object, it serves as a wedge. Usually a wedge consists of two inclined planes.

A chisel and an ax are illustrations of wedges. Perhaps the most universal form of a wedge is our common pin. Can you explain how this is a wedge?

FIG. - By means of a wedge, the stump is split.