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 172
ess than aright angle, and an angle in a segment less than a semicircle is greater thana right angle. Let ABCD be a circle, of which BC is a diameter and Ethe centre ; and draw CA, dividing the circle into the segmentsABC, ADC: (1) the angle in the semicircle BAC shall be a right angle; (2) the… … Construction. Join AE, and produce BA to F.Take any point D on the arc ADC, and join AD, DC.Proof. (1) Because EA = EB, [1. Definition U. the z.EAB = the ^EBA; [L 5. and, because EA = EC, the ^EAC^the ^ECA;.-. the whole angle BAC = the two angles ABC, ACB. [Ax. 2.But FAC, the exterior angle of the…
Euclid's Elements · Geometry · Mathematics, Greek
Internet Archive · Public Domain Mark 1.0. Free to use for anything.
