The elements of Euclid : viz, the first six books, together with the eleventh and twelfth : the errors, by which Theon, or others, have long ago vitiated these books, are corrected, and some of Euclid's demonstrations are restored : also, The book of Euclid's data, in like manner corrected (1834)
Euclid, Euclid, Simson, Robert, 1687-1768 · Philadelphia : Desilver & Thomas · leaf 88
BOOK IV. THE ELEMENTS OF EUCLID. 85 r … CD meeting one another in the point D, from which draw (12. 1.)DE,DF,DG perpendiculars to AB, A BC, CA: and because the angle EBDis equal to the angle FED, for theangle ABC is bisected by BD, andthat the right angle BED is equal tothe right angle BED, the two tri-angles EBD, EBD have two anglesof…
Mathematics, Greek · Geometry · Trigonometry
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