NickE
Academy Player
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!
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A rugby ball is an "prolate spheroid"
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
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
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NickE
Academy Player
Indeed - clever stuff! Unfortunately the 'random question' I had to answer to join this Forum only allowed a choice of 'round' or 'oval'.
Ovoid
NickE
Academy Player
Yep but I went for 'avoid' and answered a question on how many points there are for a try instead!
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