1) Considering that this quarter circle is one sector of the unit circle and that
2) Let's sketch this out to better grasp the idea:
Note that the first coordinate will be given by its cos(theta), and the second one by its sine(theta)
3) Based on that principle, we can tell the following:
As the holes need to be drilled by the machine, so we need to find approximations to those coordinates:
Thus, these are the coordinates to be put into the computer.