Definition:Perimeter

Definition

The perimeter of a plane figure is the length of its boundary.

Also defined as

By extension of its definitions as the length of its boundary, the term perimeter is frequently used (some would argue erroneously) to mean the boundary itself.

Also see

• Results about perimeters can be found here.

Linguistic Note

The word perimeter derives from the Greek peri (meaning around) and meter (meaning measure).

Hence its literal translation is measure around.

It is pronounced with the emphasis on the second syllable: pe-rim-e-ter.

Sources

• 1937: Eric Temple Bell: Men of Mathematics ... (previous) ... (next): Chapter $\text{VIII}$: Nature or Nurture?
• 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): circumference: 2.
• 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): perimeter: 1.
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): perimeter
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): perimeter
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): perimeter
• 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): perimeter