The question I am trying to solve uses 720 teeth and asks for the minimal angular speed to correctly determine the speed of light to be 3 x10e8 at a distance of 11.45 km. I was wondering if the delta theta is 1/(2 * # of teeth) or it is always 1/720, cause my textbook seems to contradict itself in that sense and it is confusing me, also the internet has not been much help in the issue.

Thanks