 | 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.... | |
 | 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.... | |
 | William James Milne - Geometry - 1899 - 404 pages
...aqual 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 To prove angle A = angle B. Proof. Draw CD bisecting... | |
 | 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... | |
 | William James Milne - Geometry, Modern - 1899 - 258 pages
...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, 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... | |
 | 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.... | |
 | International Correspondence Schools - Civil engineering - 1899 - 722 pages
...the base produced. Thus, in Figs. 32 and33, C BD is the altitude of the triangles AB C. Via. ! 47. In an isosceles triangle, the angles opposite the equal sides are equal. Thus, in Fig. 34, AB — £C; hence, angle C = angle A. Therefore, if two angles of any triangle are... | |
 | 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... | |
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In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC be an isosceles triangle, in which the side AB is equal to the side AC ; then will the angle B be equal to the angle C. 
