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Definition 24

Similar cones and cylinders are those in which the axes and the diameters of the bases are proportional.

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Two cones are similar if the axis of the first is to the axis of the second as the base diameter of the first is to the base diameter of the second. Likewise, two cylinders are similar if the axis of the first is to the axis of the second as the base diameter of the first is to the base diameter of the second.

It can be shown that an equivalent condition is that the vertex angles of the cones are equal. Thus, all right-angled cones are similar.

Book XI Introduction - Definitions 21 through 23 - Definitions 25 through 28.

© 1997
D.E.Joyce
Clark University