Elements of geometry : containing the first six books of Euclid, with a supplement on the quadrature of the circle, and the geometry of solids : to which are added, Elements of plane and spherical geometry (1826)
Playfair, John, 1748-1819, Euclid · Philadelphia : Marot & Walter · leaf 187
iht angles as there are sides in the figure (cor. 1. 32. 1.) ; thereforeall the angles of the triangles are equal to all the angles of the rectili-neal figure, together with four right angles. But all the angles at thebases of the triangles arc greater than all the angles of the rectilineal,has… … OF GEOMETRY. BOOK 11. 4S7 Otherwise: Let the sum of all the anajles at the hases of the triaiigles=S; thesom of all the angles of the rectilineal figure BCnEF=S; the sumof the plane angles at A=X, and let R=a right angle. Then, because S-f-X=twice (32.1.) as many right angles as thereare triangles,…
Euclid's Elements · Geometry · Trigonometry
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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-68-46.webp)
