In the image above, the arc length
, L, between A and B is the same length
as the radius, R, when the angle AOB
is 1 radian
is an angular measurement.
If we draw two straight lines that cross at the centre of a circle such that the length of the circumference between them (an arc) equals the radius, then the angle between these lines is 1 radian.
The angular circumference of a circle is 2π radians, or 360 degrees, so that:
- 1 radian = 360/2π degrees = 57o 17' 44.8".