### Quick Answer

**The perimeter is defined as the distance around the outside edge of a two-dimensional shape.** The perimeter of a circle or an ellipse is referred to as the circumference.

### Full Answer

The word perimeter comes from the Greek word "peri," which means "around," and the Greek word "meter," which means "measure." The perimeter can also be easily defined as the outline of an object. The perimeter is important in a variety of applications, including finding out how much fence is needed for a yard or pasture. The perimeter can also be used to describe how far a wheel will roll in one revolution.