Wikipedia:Reference desk/Archives/Mathematics/2015 August 13

= August 13 =

3D figure
What 3D figure is to the sphere as the ellipse/oval is to the circle? GeoffreyT2000 (talk) 21:26, 13 August 2015 (UTC)
 * Ellipsoid. -- Meni Rosenfeld (talk) 21:34, 13 August 2015 (UTC)
 * (It depends a bit on how you define your terms. A sphere is the surface of revolution of a circle or half-circle about its axis; a spheroid is the surface of revolution of an ellipse or half-ellipse about its axis, so in that sense, spheroid is the answer. Of course, an spheroid is a type of ellipsoid) Smurrayinchester 19:31, 14 August 2015 (UTC)