How do you represent an angle of 150 so that you can use the casting formulas?

In order to be able to use the reduction formulas, you can represent an angle of 150 degrees, or 150 = (90 degrees + 60 degrees = (pi / 2 + 60 degrees), then we look at the function and change it to the opposite and to the sign of the angle, depending on, in which quarter is this angle; or 150 = (180 degrees – 30 degrees) = (pi – 30 gaduses) then we look at the function and leave it the same and at the sign of the angle, depending on which quarter this angle is located.