The elements of Euclid for the use of schools and colleges; comprising the first six books and portions of the eleventh and twelfth books; (1903)
Euclid, Todhunter, I. (Isaac), 1820-1884, ed. edt, Simson, Robert, 1687-1768, ed. edt · London; New York, Macmillan · leaf 152
e C of a circle perpendicular tothe chord AB. Prove that the tangents at A and B meet at a pointT on CN produced. Prove also that the rectangle CN, CT equals the square on CA. 140 EUCLIDS ELEMENTS. Proposition 18. Theorem. If a straight line touch a circle^ the radius drawn from the centreof the… … Construction. For if not, let FGr be drawn from F per-pendicular to DE, meeting the circumference at B. Proof. In the AFCG, because FGO is a right z., [Hypoth. the z.FCGr is less than a right l\ [I. 17. .-. FC is greater than FG. [I. 19. But FC == FB ; [I. Definition 15. .*. FB is greater than FG,…
Euclid's Elements · Geometry · Mathematics, Greek
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![An illustration from Sidereus nuncius : magna, longeque admirabilia spectacula pandens, suspiciendaque proponens vnicuique, praesertim verò philosophis, atq[ue] astronomis, quae à Galileo Galileo ... perspicilli nuper à se reperti beneficio sunt obseruata in lunae facie, fixis innumeris, lacteo circulo, stellis nebulosis, apprime verò in quatuor planetis circa Iouis stellam disparibus interuallis, atque periodis, celeritate mirabili circumuolutis; quos, nemini in hanc vsque diem cognitos, nouissimè author depraehendit primus; atque Medicea sidera nuncupandos decreuit (1610)](https://img.insideoutlibrary.com/img/200/ia-sidereusnunciusm00gali-31-11.webp)
