Derek is calculating the measure of an angle of a regular polygon with 30 sides. Which expressions can he use to find the angle measure? A. (32x180 degrees) / 30 B. (28x180 degrees) / 30 C. [(30-2)x180 degrees] / 30 D. [(30+2)x180 degrees] / 30 E. (28x180 degrees) / 28