 | George Albert Wentworth - Geometry - 1877 - 416 pages
...respectively tcr an homologous side and acute angle of the other. TRIANGLES. PROPOSITION XXVIII. THEOREM. 112. In an isosceles triangle the angles opposite the equal sides are equal. С Let ABС be an isosceles triangle, having the sides A С and С B equal. We are to prove A = ZB... | |
 | Edward Olney - Geometry - 1879 - 502 pages
...equilateral and Us sidet are quadrants. PROPOSITION XT. 579. Theorem. — In an isosceles spherical triangle the angles opposite the equal sides are equal ; and, conversely, If ttoo angles of a spherical triangle are equal, the triangle is isosceles. DEM. — Let ABC be an isosceles... | |
 | Cornell University - 1880 - 868 pages
...tangent to a circle, the projection of one straight line upon another, four proportional magnitudes. 2. In an isosceles triangle the angles opposite the equal sides are equal to each other. Every equilateral triangle is also equiangular. An isosceles triangle is symmetric about... | |
 | William Frothingham Bradbury - Geometry - 1880 - 260 pages
...intersection E. Therefore the two triangles coincide, and are equal in all respects. THEOREM XII. 82. In an isosceles triangle the angles opposite the equal sides are equal. In the isosceles triangle ABC let AB and BC be the equal sides ; then the angle A is equal to the angle... | |
 | George Albert Wentworth - 1881 - 266 pages
...respectively to an homologous side and acute angle of the other. TRIAXGLKS. PROPOSITION XXVIII. THEOREM. 112. In an isosceles triangle the angles opposite the equal sides are equal. С Let ABC be ал isosceles triangle, having the sides AC and С B equal. We are to prove ¿ A = ¿... | |
 | Simon Newcomb - Geometry - 1881 - 418 pages
...line. 90. Def. Segments of a straight line are the parts into which it is divided. • THEOREM IX. 91. In an isosceles triangle the angles opposite the equal sides are equal to cach other. Hypothesis. ABC a triangle in which CA = CB. Conclusion. Angle A = angle B. Proof. Bisect... | |
 | Edward Olney - Geometry - 1882 - 262 pages
...is equilateral and its sides are quadrants. PROPOSITION XV. Theorem. — In an isosceles spherical triangle the angles opposite the equal sides are equal ; and, conversely, If two angles of a spherical triangle are equal, the triangle is isosceles. DEM.— Let ABC be an isosceles spherical... | |
 | 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...conversely, if two angles of a triangle are equal, the sides opposite are equal, and the triangle is isosceles. Thus, if AB = BC, arc a = arc e ; and hence,... | |
 | Edward Olney - Geometry - 1883 - 344 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...conversely, if two angles of a triangle are equal, the sides opposite are equal, and the triangle is isosceles. Thus, if AB = BC, arc a = arc e; and hence,... | |
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In an isosceles triangle the angles opposite the equal sides are equal. 
