21420289[Figure 89]
dat numerum parabolæ binario.
V.
g.
in prima pa-
rabola, nempein triangulo vt A D, ad tertiam pro-
portionalem. In quadratica vt duo tertia A D, ad
quartam. In cubica vt duo quarta, feù dimidium
A D, ad quintam. Etſic in infinitum. Sit illa vltima
proportionalis A Q. In prima parabola, nempe in
triangulo res eſt euidens, quia ſicuti triangulum
A B C, eſſet quadruplum trianguli G D H, maximi
ſibi inſcripti, ſic A D, quia A D, eſſet dupla G F,
eſſet quadrupla A Q, tertiæ proportionalis. In alijs
parabolis nè ſchemata multiplicemus, intelligamus
inſcripta triangula etiam A B C, quorum baſes A C,
diametri D B. Triangulum A B C, ad
rabola, nempein triangulo vt A D, ad tertiam pro-
portionalem. In quadratica vt duo tertia A D, ad
quartam. In cubica vt duo quarta, feù dimidium
A D, ad quintam. Etſic in infinitum. Sit illa vltima
proportionalis A Q. In prima parabola, nempe in
triangulo res eſt euidens, quia ſicuti triangulum
A B C, eſſet quadruplum trianguli G D H, maximi
ſibi inſcripti, ſic A D, quia A D, eſſet dupla G F,
eſſet quadrupla A Q, tertiæ proportionalis. In alijs
parabolis nè ſchemata multiplicemus, intelligamus
inſcripta triangula etiam A B C, quorum baſes A C,
diametri D B. Triangulum A B C, ad