2 An ellipse is just a variant of a circle, do we really need a separate class
5 We have a separate class for arcs, and those are circle variants too.
7 Maybe. The ellipse (and elliptical arc) have two focii and a rotation angle.
8 But there's no reason why those extras couldn't go into the Circle class as
11 Actually, all that's needed are the two focii and radius...