The first six books of the elements of Euclid : with a commentary and geometrical exercises ; to which are annexed a treatise on solid geometry, and short essays on ancient geometrical analysis, and the theory of transversals (1861)
Lardner, Dionysius, 1793-1859 · London : Print. for Taylor and Walton · leaf 315
an equilateral triangle be cir-cumscribed round the same circle, the baseof the equilateral triangle coinciding with aside of the square, and let the whole figurerevolve round the altitude BA of the tri-angle. A sphere will thus be describedcircumscribed by a cylinder and cone ; theentire surfaces… … The surface of the sphere is equal to four times one of itsgreat circles (240). The cylindrical surface isequal to this; and as each of the bases of thecylinder is a great circle, the entire surface ofthe cylinder is equal to six times a great circle.Hence the ratio of the surface of the sphereto…
Geometry
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