Nowe of three plattes there are made certain figures of bodyes, as the cantels and halues of all bodyes that haue but ij. plattys, and also the halues of halfe globys and canteles of a globe. Lykewyse a rounde piller, and a spyre made of a rounde spyre, slytte in ij. partes long ways. But as these formes be harde to be iudged by their pycturs, so I doe entende to passe them ouer with a great number of other formes of bodyes, which afterwarde shall be set forth in the boke of Perspectiue, bicause that without perspectiue knowledge, it is not easy to iudge truly the formes of them in flatte protacture. And thus I made an ende for this tyme, of the definitions Geometricall, appertayning to this parte of practise, and the rest wil I prosecute as cause shall serue. THE PRACTIKE WORKINGE OF +sondry conclusions geometrical.+ THE FYRST CONCLVSION. To make a threlike triangle on any lyne measurable. Take the iuste lẽgth of the lyne with your cõpasse, and stay the one foot of the compas in one of the endes of that line, turning the other vp or doun at your will, drawyng the arche of a circle against the midle of the line, and doo like wise with the same cõpasse vnaltered, at the other end of the line, and wher these ij. croked lynes doth crosse, frome thence drawe a lyne to ech end of your first line, and there shall appear a threlike triangle drawen on that line. [Illustration] _Example._ A.B. is the first line, on which I wold make the threlike triangle, therfore I open the compasse as wyde as that line is long, and draw two arch lines that mete in C, then from C, I draw ij other lines one to A, another to B, and than I haue my purpose. THE .II. CONCLVSION If you wil make a twileke or a nouelike triangle on ani certaine line. [Illustration] Consider fyrst the length that yow will haue the other sides to containe, and to that length open your compasse, and then worke as you did in the threleke triangle, remembryng this, that in a nouelike triangle you must take ij. lengthes besyde the fyrste lyne, and draw an arche lyne with one of thẽ at the one ende, and with the other at the other end, the exãple is as in the other before. [Illustration] THE III. CONCL. To diuide an angle of right lines into ij. equal partes. First open your compasse as largely as you can, so that it do not excede the length of the shortest line y^t incloseth the angle. Then set one foote of the compasse in the verye point of the angle, and with the other fote draw a compassed arch frõ the one lyne of the angle to the other, that arch shall you deuide in halfe, and thẽ draw a line frõ the ãgle to y^e middle of y^e arch, and so y^e angle is diuided into ij. equall partes. [Illustration] _Example._ Let the triãgle be A.B.C, thẽ set I one foot of y^e cõpasse in B, and with the other I draw y^e arch D.E, which I part into ij. equall parts in F, and thẽ draw a line frõ B, to F, & so I haue mine intẽt. THE IIII. CONCL.