> >> Spherical geometry allows you to calculate _directly_ on the sphere > >> without using a projection ... you simple use LatLon in radian > >> degrees. > > > > True, but it's not really trivial. > > A rectangle with 89.55°, 90.1°, 89.89°, 90,01° is no rectangle. > What's the definition of "rectangle" in non-euclidean geometry anyway?