I work it out from scratch each time because I can't rememer forumulas very easily
I know that 180degrees = pi radians so that is where i start.
$$180^0=\pi^c\\\\
1^0 = \frac{\pi^c}{180}\\\\
\mbox{therefore}\\\\
x^0=x\times \frac{\pi}{180}\mbox{ radians }$$