 | Adelia Roberts Hornbrook - Geometry - 1895 - 224 pages
...that the equal sides shall coincide, and show the truth of the following theorem : PRINCIPLE 17. — In an isosceles triangle the angles opposite the equal sides are equal. 13. In the isosceles triangle ABC the angle BAC is 70°. How many degrees are there in each exterior... | |
 | George Albert Wentworth - Mathematics - 1896 - 68 pages
...third side of the first triangle is greater than the angle opposite the third side of the second. 154. In an isosceles triangle the angles opposite the equal sides are equal. 155. Cor. An equilateral triangle is equiangular, and each angle contains 60°. 156. If two angles... | |
 | Electrical engineering - 1897 - 672 pages
...to the base extended. Thus, in Figs. 33 and C 34, BD is the altitude FIG. 33. of the triangles ABC. In an isosceles triangle, the angles opposite the equal sides are equal. Thus, in Fig. 35, AB = BC; hence, angle C= angle A. In any isosceles triangle, if a perpendicular be... | |
 | George Washington Hull - Geometry - 1897 - 408 pages
...contrary to the hypothesis that AB is greater than DE. Hence Z C> Z F. QKD PROPOSITION XXIV. THEOREM. 63. In an isosceles triangle, the angles opposite the equal sides are equal. D Given—The triangle ABC, isosceles, with AC= EC. To Prove— Z A — Z B. Dem.—Draw CD perpendicular... | |
 | Webster Wells - Geometry - 1898 - 250 pages
...contrary to the hypothesis that BC is > EF. Then, if ZA can be neither equal to Z D, nor < Z D, PROP. XXX. THEOREM. 93. In an isosceles triangle, the angles opposite the equal sides are equal. D Given ^1(7 and BCtiie equal sides of isosceles To Prove ZA = Z B. Proof. Draw line CD _L AE. In rt.... | |
 | International Correspondence Schools - Surveying - 1898 - 518 pages
...to the base produced. Thus, in Figs. 32 and33, CBD is the altitude of the triangles AB C. PlC. 47. In an isosceles triangle, the angles opposite the equal sides are equal. Thus, in Fig. 34, AB = BC; hence, angle C = angle A. Therefore, if two angles of any triangle are equal,... | |
 | Webster Wells - Geometry - 1899 - 450 pages
...contrary to the hypothesis that BC is > EF. Then, if ZA can be neither equal to ZD, nor < ZD, PROP. XXX. THEOREM. 93. In an isosceles triangle, the angles opposite the equal sides are equal. D Given AC and BC the equal sides of isosceles A ABC. To Prove ZA = ZB. Proof. Draw line CD ± AB.... | |
 | Webster Wells - Geometry - 1899 - 424 pages
...second.] (§»1) But each of these conclusions is contrary to the hypothesis that BC is > EF. PROP. XXX. THEOREM. 93. In an isosceles triangle, the angles opposite the equal sides are equal. DB Given AC and BC the equal sides of isosceles A ABC. To Prove ZA = Z B. Proof. Draw line CD _L AB.... | |
 | George Albert Wentworth - Geometry - 1899 - 496 pages
...always true, just as the converse of a theorem is not always true. PROPOSITION XXII. THEOREM. 145. In an isosceles triangle the angles opposite the equal sides are equal. BDC Let ABC be an isosceles triangle, having AB and AC equal. To prove that ZB = Z C. Proof. Suppose... | |
 | Harvard University - Geometry - 1899 - 39 pages
...respectively equal to a side and the two adjacent angles of the other, the triangles are equal. THEOREM III. In an isosceles triangle the angles opposite the equal sides are equal „ Conversely, if two angles of a triangle are equal, the triangle is isosceles. THEOREM IV. If two... | |
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In an isosceles triangle, the angles opposite the equal sides are equal. 
