The measure of an angle is determined by the amount of rotation from the initial side to the terminal side.  In radians, one complete counterclockwise revolution is 2π and in degrees, one complete counterclockwise revolution is 360°.  So, degree measure and radian measure are related by the equations

From the latter, we obtain the equation 1 radian = .  This leads us to the rule to convert radian measure to degree measure.  To convert from radians to degrees, multiply the radians by .

Example 1: