Two cases of portions of a circles are shown in underlying first figure. I think the surface of revolution in first case around axis AB will be a prolate speriod (second figure). Please correct me if I am wrong. In second case I have drawn the surface of revolution and attach the figure below (third figure, please ignore the small prolate spehriod shape inside the bigger surface). My question is, what is the specific name (in geometry literature) of this geometic shape? It is like a apple with two end curled inside.
