Is a rugby ball oval or round? Obvious answer is of course oval but mathematically it is circular (round) in one plane - looking end on - and oval in the others. I think I need to get out more!
Is a rugby ball oval or round? Obvious answer is of course oval but mathematically it is circular (round) in one plane - looking end on - and oval in the others. I think I need to get out more!
A spheroid, or ellipsoid of revolution is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters.
If the ellipse is rotated about its major axis, the result is a prolate (elongated) spheroid, like an American football or rugby ball.
If the ellipse is rotated about its minor axis, the result is an oblate (flattened) spheroid, like a lentil. If the generating ellipse is a circle, the result is a sphere. All of the giant planets plus Mars, Earth and Venus are oblate spheroids