All rights reserved. Dow Jones: The Dow Jones branded indices are proprietary to and are calculated, distributed and marketed by DJI Opco, a subsidiary of S&P Dow Jones Indices LLC and have been licensed for use to S&P Opco, LLC and CNN.HAttr:198656;20,1914,411,15;12,2;109,191,246,255\}\{T:a,HAttr:198658;431,1914,34,15;431,1914,34,15;0,0,0,0;0,0,0,0,href:/services/terms.html,rel:nofollow\{Text: Terms,HAttr:198656;431,1914,34,15;12,2;109,191,246,255\}\}\{Text: under which this service is provided to you.
Thus 2 radians equals 360 degrees. This means that 1 radian = 180/ degrees, and 1 degree = /180 radians. The reason for this is that so many formulas become much easier to write and to understand when radians are used to measure angles. A very good example is provided by the formula for the length of a circular arc.
The other answers are correct, but let me add how I answer this question. As a graphics and game programmer, I often have to convert between degrees and radians, for all sorts of things. degrees to radians -> divide by 57.29578. radians to degrees -> multiply by 57.29578. Hehe, easy. That magic number has been rattling around my head for about 20 years. It's an approximation of 180/pi.