angles in radians, so you want to convert 90 degrees to radians (the opposite). To do that use Rad(A).
(If you are so mixed up, why don't you try both functions by trial and error and see what happens?)
When using the ° symbol, you have to write some number or variable preceding it. So in your case you want to write A°.…
Added by Vicente Soler at 8:39am on November 22, 2009