 | 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.... | |
 | 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... | |
 | 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.... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...angles are opposite the legs. Consult Prop. 37, Cor. III. and Prop. 8. Proposition 41. Theorem. 52. In an isosceles triangle, the angles opposite the equal sides are equal. HINT. Draw a line bisecting the vertical angle. COB. An equilateral triangle is also equiangular. Proposition... | |
 | Adelia Roberts Hornbrook - Arithmetic - 1900 - 428 pages
...isosceles triangle so that the equal sides coincide. Can you see that the following statement is true ? In an isosceles triangle the angles opposite the equal sides are equal. 352. How many degrees are there in each angle of the isosceles triangle ABC? Explain. 353. How many... | |
 | International Correspondence Schools - Coal mines and mining - 1900 - 720 pages
...base, or to the base extended. Thus, in Figs. 33 and altitude in BD is the _ 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... | |
 | 1900 - 728 pages
...the base, or to the base extended. Thus, in Figs. 33 and 34, BD is the altitude 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... | |
 | Alan Sanders - Geometry, Modern - 1901 - 260 pages
...of the other pair of vertical angles. Find the values of the four angles. PROPOSITION X. THEOREM 81. In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC be an isosceles A, having AB = BC. To Prove Z A = Z C. Proof. Draw BD bisecting AC. (§ 55.) B and D are each equally... | |
 | Henry Parker Manning - Geometry, Non-Euclidean - 1901 - 120 pages
...the included angle, of one Kqual, respectively, to the corresponding parts of the other. 4. Theorem. In an isosceles triangle the angles opposite the equal sides are equal. Bisect the angle at the vertex and use (3). 5. Theorem. The perpendiculars erected at the middle points... | |
 | Henry Parker Manning - Geometry, Non-Euclidean - 1901 - 116 pages
...the included anyle, of one equal, respectively, to the corresponding parts of the other. 4. Theorem. In an isosceles triangle the angles opposite the equal sides are equal. Bisect the angle at the vertex and use (3). 5. Theorem. The perpendiculars erected at the middle points... | |
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In an isosceles triangle, the angles opposite the equal sides are equal. 
