Ball, W. W. Rouse (Walter William Rouse), 1850-1925 · London, Macmillan · leaf 332
their parts.Pascal, stimulated no doubt by the injunction against readingit, gave up his playtime to the new amusement, and in a fewweeks had discovered for himself several properties of recti-linear figures, and in particular the proposition in question. His proof is said* to have consisted in… … if the paper be creased so that A is turned over to D, as alsoB and (7, we get B^FBB, A=FDE, and G = EDC; henceA+B-\-G = EDF4- FDB + EDG = tt. But we can only provethese relations on the assumption that when the paper is foldedover BF and ^i^ will lie along BF, and thus that BF=FA= FD,and similarly…
Mathematical recreations · Geometry · Astrology · Space and time · Matter · Magic squares
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