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Example.
Considering of Solides called Prismata, there are two kindes, the one directe •• vpright, whose Paralelogrammes are Perpendiculare to their Base, the other ••••lique or declining, whose Paralelogrammes are obliquely situate on their bases. ••f either I minde to propound an example, although one rule suffise them bothe. ••dmit therfore ABCDEF a direct or vpright Triangular Prisma, hauing 〈◊〉〈◊〉 three sides of his base ED 3, DC 4, EC ••, his altitude AD 10, so that by 〈◊〉〈◊〉 rules geuen in Planimetra I finde the Area of either Triangle or base 6, the Paralelogrammes AFED 30, ABCD 40 FBCE 50, all these ioyned toge∣ther,
For the Crassitude I search the altitude of either Solide, which in the vpright Prisma is, the ereared side of any of his Paralelogrammes, as AD, BC, or FE. ••or they are all equall, euery one of them being 10, but the altitude of the declining Quadrangular Prisma is the Perpendicular OR, falling from O the top of the Prisma perpendicularly on MR a line drawne in the plaine wheron the body re∣••••eth, 10 therfore multiplied in 6, produceth 60, the Solide quantitie of that Pris∣••a: Also the altitude OC being founde by mensuration 12. multiplied in 18 the ••ase, bringeth 216, and that is the Solide capacitie of the declining Prisma IKLMNO.
Although these common péeces. K.L. are moten as is tofore taught, yet 〈◊〉〈◊〉 may readely thus measure them, multiplye the length with the bredth, ••nd the Product in the thicknesse, so haue ye the content or Crassitude.
The content of K 216 Cubicall foote, the Crassitude of L 216 square foote.