unit circle

English

The circumference of a unit circle (sense 1) is 2π units.
a diagram of the unit circle (sense 2) and its trigonometry

Noun

unit circle (plural unit circles)

  1. (usually) A circle of radius 1.
  2. (trigonometry, occasionally, the unit circle) The circle of radius 1 with centre at the origin, used in defining trigonometric functions.

Translations