| Franklin Ibach - Geometry - 1882 - 208 pages
...and an acute angle of the other. ВЕЪАТКШ BETWEEN THE PARTS OF A TRIANGLE. THEOREM XXXI. 94. In an isosceles triangle, the angles opposite the equal sides are equal. In the isosceles A ABC, let AC and B С be the equal sides. С ADB To prove that ¿- a = ¿- b. Let... | |
| Edward Olney - Geometry - 1883 - 352 pages
...chords are equal, the arcs are, and hence the angles subtended by these arcs. 223. COROLLARY 3. — In an isosceles triangle the angles opposite the equal sides are equal ; and, conversely, if two angles of a triangle are equal, the sides opposite are equal, and the triangle... | |
| Alfred Hix Welsh - Geometry - 1883 - 326 pages
...equal in all their parts (Th. IV)', and, consequently, the angle B is equal to the angle C. Therefore, in an isosceles triangle, the angles opposite the equal sides are equal. Cor. I.—An equilateral triangle is equiangular. For, if AB equals AC, then, by the Theorem just proved,... | |
| Engineering - 1884 - 616 pages
...any exterior angle is greater than either of the opposite interior, QED 35. We shall next show that, In an isosceles triangle, the angles opposite the equal sides are equal. In the triangle ABC, let AB = AC {Fig. 2), Fig.2 "Turn the triangle ABC over, and suppose it to take... | |
| F. B. Stevens - Examinations - 1884 - 202 pages
...contained by the whole and one of the parts may be equal to the square on the other part. (LEGENDRE.) 1. In an isosceles triangle the angles opposite the equal sides are equal. 2. In equal circles, equal chords are equally distant from the centres ; and of two unequal chords... | |
| George Albert Wentworth - 1884 - 264 pages
...each. 39. Corollary. Two right triangles are equal if their legs are equal, each to each. 40. Theorem. In an isosceles triangle the angles opposite the equal sides are equal. 41. Corollary. An equilateral triangle is equiangular. 42. Theorem. If in a triangle two angles are... | |
| W. Cain - 1884 - 156 pages
...any exterior angle is greater than either of the opposite interior, QED 35. We shall next show that, In an isosceles triangle, the angles opposite the equal sides are equal. In the triangle ABC, let AB = AC (Fig. 2), Turn the triangle ABC over, and suppose it to take the position... | |
| George Bruce Halsted - Geometry - 1885 - 389 pages
...PROOF. By 133, from a cut off BD = c. By 100, join AD. Then, because BD = c, :. £ BDA = £ BAD. (126. In an isosceles triangle the angles opposite the equal sides are equal.) And, by 142, the exterior ^ BDA of A CD A > the opposite interior ^ C, :. also £ BAD >£C. Still more... | |
| Charles Davies, Adrien Marie Legendre - Geometry - 1885 - 538 pages
...respects, the equal sides lie opposite the equal angles ; and conversely. PROPOSITION XI. THEOREM. In an isosceles triangle the angles opposite the equal sides are equal. BOOK I. Join the vertex A and the middle point D of the base BC. Then, AB is equal to AC, by hypothesis,... | |
| George Bruce Halsted - Geometry - 1886 - 394 pages
...£ACB, (168. If a transversal cuts two parallels, the alternate angles are equal.) 4 ACB = 4 ABC, (126. In an isosceles triangle the angles opposite the equal sides are equal.) 4 ABC = 4 DAN, (169. If a transversal cuts two parallels, the corresponding angles are equal.) (128.... | |
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