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 155
AC meetsthem, the alternate angles BAC,ACD are equal (29. I.); for thesame reason, the angle CDE isequal to the angle ACD; where-fore also BAC is equal to CDE:and because the triangles ABC, B C E DCE have one angle at A equal to one at D, and the sides aboutthese angles proportionals, viz. BA to… … * « See Note. ■■i^^:.. BOOK vr. THE ELEMENTS OF EUCLID. 153 the two angles ABC, BAG5 add the common angle ACB, thenthe atigles ACE, ACB are equal to the angles ABC, BAC, ACB:but ABC, BAC, ACB are equal to two right angles (32. l.)^therefore also the angles ACE, ACB are equal to two right an-gles:…
Mathematics, Greek · Geometry · Trigonometry
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
