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 224
223 let it meet the circle again in P; let CO be perpendicular to BN; andlet it meet AE in R. It is evident that MN=AB-f AC-f BC; and that LN=AB+AC•—BC. Now, because BD is bisected in E, (3. 3.) and DN in A, BNis parallel to AE, and is therefore perpendicular to BD, and the tri-angles DAE, DNB are… … Iheir hases, [i. 6.), ACAD : AD^:: AR.AE : AE^, and alternatelyACAD : AR.AE :: AD^ : AES and 4ACAD : 4AR.AE :: AD« •AE^. But 4AR.AE=2ARx2AE=NP.NB = MN.NL; therefore4ACAD : MN.NL ;: AD^: AE^. But AD : AE ;: R ; cos. DAE(l)=cos. i (BAG): Wherefore 4ACAD ; MN.NL :: R^: (cos. hBACy. Now4ACAD is four…
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-390-270.webp)
