If I'm rolling a ball across the screen I can use distanceTravelled = 2*pie*radius*transform.rotation/360.
Why don't I have to convert the rotationAngle to degrees before I do the math? Since i'm using 360 (in degrees) I thought I would have had to: AE normally hands out the radian value when you ask about angle, no?
AE does rotation in degrees so your rotation angle is already in degrees. You're actually doing the conversion in your formula by multiplying the fraction of one complete rotation in degrees (rotation/360) by 2*pi radians (which is also one complete rotation.