 | 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... | |
 | 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... | |
 | James Howard Gore - Geometry - 1898 - 232 pages
...obtuse-angled triangle the sum of the acute angles is less than a right angle. PROPOSITION XVII. THEOREM. 93. In an isosceles triangle the angles opposite the equal sides are equal. Let ABC be an isosceles triangle in which AC and BC are the equal sides. To prove that Z A = Z B. Draw... | |
 | Webster Wells - Geometry - 1898 - 284 pages
...hypothesi£ that BC is > EF. Then, if ZA can be neither equal to ZD, nor < ZD, ZA> 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 = Z B. Proof. Draw line CD _L AB.... | |
 | 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,... | |
 | William James Milne - Geometry, Modern - 1899 - 258 pages
...opposite the «qual sides compare in size ? 2. How do the angles of an equilateral triangle .compare? Theorem. In an isosceles triangle the angles opposite the equal sides are equal. Data : Any isosceles triangle, as ABC, in which C = BC. To prove angle A = angle B. Proof. Draw CD... | |
 | George Albert Wentworth - Geometry, Plane - 1899 - 278 pages
...the converge of a theorem is not always true. BOOK I. PLANE GEOMETRY. PROPOSITION XXII. THEOREM. 145. In an isosceles triangle the angles opposite the equal sides are equal. • B na Let ABC be an isosceles triangle, having AB and AC equal. To prove that ZB = Z C. . Proof.... | |
 | George Albert Wentworth - Geometry, Solid - 1899 - 246 pages
...angle of the other. 144. Two right triangles are equal if their legs are equal, each to each. 145. In an isosceles triangle the angles opposite the equal sides are equal. 147. If two angles of a triangle are equal, the sides opposite the equal angles are equal, and the... | |
 | Webster Wells - Geometry - 1899 - 424 pages
...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.... | |
 | 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. 
