arc length of the path that surrounds an area

In geometry, perimeter is the distance around a flat object. For example, all four sides of a square rhombus have the same length, so a rhombus with side length 2 inches would have a perimeter of 8 inches (2+2+2+2=8).

For a polygon, the perimeter is simply the sum of the length of all of its sides.[1] For a rectangle, the perimeter is twice the sum of its length and width ().[2] Perimeter can also be calculated for other planar figures, such as circle, sector and ellipse.[3]

Real-life objects have perimeters as well. A football field, including the end zones, is 360 feet long and 160 feet wide. This means that the perimeter of the field is 360+160+360+160=1040 feet.

The perimeter of a circle is usually called the circumference.[3] It may be calculated by multiplying the diameter times "Pi". Pi is a constant which is approximately equal to 3.14159; however, the places to the right of the decimal are endless. The number of places used depends on the accuracy required for the result.

Related pagesEdit


  1. "Perimeter and Area". Retrieved 2020-09-25.
  2. "List of Geometry and Trigonometry Symbols". Math Vault. 2020-04-17. Retrieved 2020-09-25.{{cite web}}: CS1 maint: url-status (link)
  3. 3.0 3.1 "Perimeter". Retrieved 2020-09-25.