Radians and degrees?
When doing trigonometry on the unit circle, radian measure is way easier for me to use in the calculations. If doing angles as fractions, using degree measure is easier because that number, 360, has the most even fractional divisions.
The Powers-That-Be have designated ‘Radians’ as THE International [SI] unit of circular/angular measurements......In a hundred years ‘degrees’ with respect to circles will be an anachronism, like pecks and bushels........................