# Full text: Cavalieri, Bonaventura: Geometria indivisibilibvs continvorvm

LIBER IV. guli, ad portionem parabolæ dicto parallelogrammo inſcri-
ptam ratio nota erit.

Sit parabola, cuius baſis, FG, ad axim, vel diametrum, CX, or-
dinatim applicata; ad baſim autem, FG, ſit etiam ordinatim appli-
cata, AN, vtcunq; diuidens baſim, FG, in puncto, N, ſiat autem
parallelogrammum, RN, & triangulum, AFN, ſublateribus, A
N, NF, vel ſub, AN, NG; Vel ſint duæ vtcunque ad baſim, FG,
ordinatim applicatæ, AN, CX, ſiat autem parallelogrammum, & triangulum ſub, AN, NX, vel ſub, CX, XN. Dico parallelogram-
mum, RN, veltrian-
portionem, AFN,
parabole, FCG, pa-
rallelogrammo, RN,
inſcriptam, eſſe in ra-
tione nota. Similiter
parallelogrammum,
ZX, & triangulum,
nem, ACXN, habe-
re rationem notam. Producatur, CX, vt-
cunque in, E, & cir-
ca ſemiaxes, vel ſemi-
diametros coniuga-
tas, FX, XE, intel-
ligatur deſcriptus ſe-
micirculus, velſemi-
ellipſis, FEG, pro-
ducantur deinde, RF, ZN, indeſinitè, ſecetque, ZN, curuam ſe-
micirculi, vel ſemiellipſis, FEG, in puncto, O, & compleantur pa-
rallelogramma, VN, RX, ſumatur deindein, FN, vtcunq; pun-
ctum, S, per quodipſi, CE, parallela ducatur, YT, ſecans curnam
parabolæ in, I, curuam autem, FEG, in, M; eſt ergo, AN, ad, I
S, vt rectangulum, GNF, ad rectangulum, GSF, eſt autem etiam
tem, RN, NV, parallelogramma in eiſdem baſibus, & altitudini-
bus cum portionibus, AFN, NFO, & punctum, S, ſumptum eſt