 | George Albert Wentworth - Mathematics - 1896 - 68 pages
...equiangular triangle, each angle is one-third of two right angles, or two-thirds of one right angle. 145. The exterior angle of a triangle is equal to the sum of the two opposite interior angles. 146. Cor. The exterior angle of a triangle is greater than either of the opposite interior angles.... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 374 pages
...B. §70 [Being base angles of an isosceles triangle.] , But angle »= angle A + angle B. § 58 [The exterior angle of a triangle is equal to the sum of the two opposite interior angles. Substituting A for B, n = 2A. But n is measured by arc B.£. § 185 Hence half of «, or A, is measured... | |
 | George Washington Hull - Geometry - 1897 - 408 pages
...Substituting Z A for Z a, and Z C for Z c, we have Z v4 + Z d + ZC= two right angles. QED 49. COR. 1.—An exterior angle of a triangle is equal to the sum of the two opposite interior angles. 50. COR. 2.—An exterior angle of a triangle is greater than either of the opposite interior angles.... | |
 | Joseph Johnston Hardy - Geometry, Analytic - 1897 - 398 pages
...Two angles whose sides are perpendicular, each to each, are either equal or supplementary. 13. The exterior angle of a triangle is equal to the sum of the two opposite interior angles. 14. Two right angles are equal if the hypotenuse and an acute angle of one are equal respectively to... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 376 pages
...angle BXD is measured by one-half the sum of the arcs BDa.ndAC. Join A and D. Now m — s + ze. § 58 [An exterior angle of a triangle is equal to the sum of the opposite interior angles.] But angle s is measured by ^ arc BD. § 189 And angle w is measured... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 374 pages
...angle BXD is measured by one-half the sum of the arcs BD and AC. Join A and D. Now w — s + w. § 58 [An exterior angle of a triangle is equal to the sum of the opposite interior angles.] But ' angle J is measured by ^ arc BD. § 189 And angles is measured... | |
 | Webster Wells - Geometry - 1898 - 264 pages
...85. Cor. I. It follows from the above demonstration that Z.BCD = Z.ECD + Z.BCE = ZA + ZB; hence 1. An exterior angle of a triangle is equal to the sum of the two opposite interior angles. 2. An exterior angle of a triangle is greater than either of the opposite interior angles. 87. Cor.... | |
 | Webster Wells - Geometry - 1898 - 250 pages
...Cor. I. It follows from the above demonstration that Z BCD = Z EC/) + Z BCE = ZA + ZB; hence 1. .<4n exterior angle of a triangle is equal to the sum of the two opposite interior angles. 2. An exterior angle of a triangle is greater than either of the opposite interior angles. 86. Cor.... | |
 | George Albert Wentworth - Geometry - 1899 - 496 pages
...COR. 7. In an equiangular triangle, each angle is one third of two right angles, or 60°. 137. COR. 8. An exterior angle of a triangle is equal to the sum of the two opposite interior angles, and therefore greater than either of them. PROPOSITION XIX. THEOREM. 138. The sum of two sides of a... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...COB. IV. In a right triangle, the two acute angles are complementary, Proposition 38. Theorem. 49. An exterior angle of a triangle is equal to the sum of the two opposite interior angles. COB. An exterior angle of a triangle is greater than either of the two opposite interior angles. Ex.... | |
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An exterior angle of a triangle is equal to the sum of the two opposite interior angles. 
