Philippi Lansbergii Triangvlorvm geometriae libri qvatvor : in quibus novâ & perspicuâ methodo, & apodeixei [romanized], tota ipsorum triangulorum doctrina explicatur .. (1631)
Lansberge, Philippe van, 1561-1632 · Amsterdami : Apud Gvilielmvm Blaevw · leaf 129
mplitudinem in Sphz- rico Triangulo,menfurat arcus maxi- mi circuli, ex angulo tanquam polo defcriptus dictum angulü fübtendens. — Jta in adjantla. Diagrapha , arcis. B C, men [erat - angulum B AC : edt enim arcus magn circuli , ex A. angulo. , tamquam polo defcriptus , ,ipfem augulum fd-. tendens.… … B C eff normalis circumferemio C & : € proinde anga- A. 2 emus
Trigonometry -- Early works to 1800
Internet Archive · Fisher - University of Toronto · Public domain (published before 1931). Free to use for anything.
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![An illustration from Nicolai Copernici Torinensis De reuolutionibus orbium coelestium, libri VI : Habes in hoc opere iam recens nato, & aedito, studiose lector, motus stellarum, tam fixarum, quàm erraticarum, cum ex ueteribus, tum etiam ex recentibus obseruationibus restitutos: & nouis insuper ac admirabilibus hypothesibus ornatos. Habes etiam tabulas expeditissimas, ex quibus eosdem ad quoduis tempus quàm facillime caculare poteris. Igitur eme, lege, fruere. [Line in Greek] (1543)](https://img.insideoutlibrary.com/img/200/ia-nicolaicopernici00cope-65-42.webp)
