LEMMA IV.
SI propoſita quæcumque figura plana vni regulæ paral-
lelis quotcumque lineis ita ſecari poſſit, vt conceptæ
in figura rectæ lineæ integræ ſemper exiſtant: Ipſa ex pa-
rallelogrammis rectilineis, aut curuilineis, ſeu ex figuris
in alteram partem deficientibus, regula eadem, compo-
netur.
lelis quotcumque lineis ita ſecari poſſit, vt conceptæ
in figura rectæ lineæ integræ ſemper exiſtant: Ipſa ex pa-
rallelogrammis rectilineis, aut curuilineis, ſeu ex figuris
in alteram partem deficientibus, regula eadem, compo-
netur.
Sit quæcumque figura plana, SPFR, talis tamen, vt ſecta quot-
cumq; vni regulæ, vt, FE, parallelis, conceptæ in ipſa rectæ lineę
integræ ſint. Dico ipſam, velex parallelogrammis rectilineis, aut
343[Figure 343]
curuilineis, vel ex figuris in al-
teram partem deficientibus,
reg. eadem, FE, componi.
Sint enim ductæ, SA, FE, op-
poſitæ tangentes figuræ, SPF
R, regula eadem, FE, quibus
incidat quomodocumq; recta
linea, AE, moueatur autem, F
111. lib. 1 E, verſus, SA, ſemperæquidi-
ſtanter eidem, SA, donec illi
congruat, interim verò punctum, E, ita in ipſa feratur, vt deſcri-
bat lineam, ENA, cum, AE, figuram, ANE, comprehenden@em,
quæ eidem, SPFR, ſit æqualiter analoga iuxta regulam, FE; in
eadem integris exiſtentibus parallelis ipſi, FE, ad ambitum, ANE,
terminantibus: rurſus feratur recta linea, AE, verſus ambitum, A
NE, ſemper ipſi, AE, æquidiſtanter donec totam pertranſierit fi-
guram, ANE, adnotentur autem contactus lineæ ſic
cumq; vni regulæ, vt, FE, parallelis, conceptæ in ipſa rectæ lineę
integræ ſint. Dico ipſam, velex parallelogrammis rectilineis, aut
teram partem deficientibus,
reg. eadem, FE, componi.
Sint enim ductæ, SA, FE, op-
poſitæ tangentes figuræ, SPF
R, regula eadem, FE, quibus
incidat quomodocumq; recta
linea, AE, moueatur autem, F
111. lib. 1 E, verſus, SA, ſemperæquidi-
ſtanter eidem, SA, donec illi
congruat, interim verò punctum, E, ita in ipſa feratur, vt deſcri-
bat lineam, ENA, cum, AE, figuram, ANE, comprehenden@em,
quæ eidem, SPFR, ſit æqualiter analoga iuxta regulam, FE; in
eadem integris exiſtentibus parallelis ipſi, FE, ad ambitum, ANE,
terminantibus: rurſus feratur recta linea, AE, verſus ambitum, A
NE, ſemper ipſi, AE, æquidiſtanter donec totam pertranſierit fi-
guram, ANE, adnotentur autem contactus lineæ ſic