How would you design a spherical compass with“squared degrees” for space travel?

"2 radians equals 360 degrees. Thus 1 radian = 180/ degrees, and 1 degree = /180 radians. d(A,B) = R a /180, These formulas can be checked by noticing that the arc length is proportional to the angle, and then checking the formula for the full circle, i.e., when a = 2 radians (or 360 degrees)"