Unit Descriptions

1 Revolution (or cycle, full circle, turn, rotation) is equal to exactly 360° (degrees of arc) or 2π radians (SI unit) or 400 gradians or 4 right angles.

Circle:A circle is a simple closed shape. It is the set of all points in a plane that are at a given distance from a given point, the centre; equivalently it is the curve traced out by a point that moves so that its distance from a given point is constant. The distance between any of the points and the centre is called the radius.