Definition:Perimeter

Definition

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

Also defined as

By extension, the term perimeter is also frequently used (some would argue erroneously) to mean the boundary itself.

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
• 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