Times Square in New York City has the coordinates (as per Google Maps):
The Barrymore Theater has the coordinates (again, as per Google maps):
Given that latitude and longitude are not rectilinear coordinates, how should I translate the coordinates for the Barrymore Theater into a radius from Times Square and an angle relative to due north? These would be like polar coordinates, with Times Square as the pole and due north as 0º.
I know that the Cartesian-to-Polar transformation is
radius = sqrt(x^2 + y^2) angle = tanh(y / x)
Is this a suitable approximation if I just plug in latitude and longitude for
y? At what distance scale would it start to break down, and how badly?