I would expect that RadianToDegrees() takes as argument a floating point value (double or long double) representing an angle in radians and returns that angle expessed in degrees. DegreesToRadian() would take an angle expressed in degrees and return the angle expressed in radians. The two are related such that

RadianToDegrees(DegreesToRadian(x)) == x % 2*PI

Radians to degrees can be calculated as:

degrees = radians * 180 / PI;

RadianToDegrees(DegreesToR

Radians to degrees can be calculated as:

degrees = radians * 180 / PI;