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 132
C, asBA to AC; and that BD is also to DC, as BA to AF (11. 5.):therefore I3A is to AC, as BA to AF (9. 5.); wherefore AC isequal to AF (5. 1.), and the angle AFC equal (o. 1.) to the angleACF; but the angle AFC is equal to the outward angle EAD,and the angle ACF to the alternate angle CAD:…
Mathematics, Greek · Geometry · Trigonometry
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