 | Edward Rutledge Robbins - Geometry, Plane - 1906 - 268 pages
...angles within the triangle, at the other vertices are the opposite interior angles. [ZA and Z ('.] 108. THEOREM. An exterior angle of a triangle is equal to the sum of the opposite interior angles. Given: A ABC; exterior Z ABD. To Prove : Z ABD = ZA + Z C. Proof : Suppose BP to be drawn through B... | |
 | Isaac Newton Failor - Geometry - 1906 - 431 pages
...equal. 157 COROLLARY 4. Each angle of an equilateral triangle is 60°. PROPOSITION XII. THEOREM 158 An exterior angle of a triangle is equal to the sum of the opposite interior angles. HYPOTHESIS. ACD is an exterior angle of the triangle ABC. CONCLUSION. Z ACD = ^ A + Z B. PROOF Z ACD... | |
 | Isaac Newton Failor - Geometry - 1906 - 440 pages
...equal. 157 COROLLARY 4. Each angle of an equilateral triangle is 60°. PROPOSITION XII. THEOREM 158 An exterior angle of a triangle is equal to the sum of the opposite interior angles. HYPOTHESIS. ACD is an exterior angle of the triangle ABC. CONCLUSION. Z ACD = ZA + Z B. PROOF Z ACD... | |
 | Wisconsin. Department of Public Instruction - Education - 1906 - 124 pages
...perpendicular to the sides of another angle, the angles are either equal or supplementary. 20. Any exterior angle of a triangle is equal to the sum of the opposite interior angles. 21. The sum of the interior angles of a triangle is equal to two right angles. . Cor. 1. In a right... | |
 | International Correspondence Schools - Building - 1906 - 634 pages
...therefore, the third angle is equal to 180° - (44° 21' 30" + 110° 53' 45") = 24° 44' 45". Ans. (4) An exterior angle of a triangle is equal to the sum of the opposite-interior angles (Art. 68) . The sum of the opposite-interior angles is, therefore, 104°... | |
 | Edward Rutledge Robbins - Geometry - 1907 - 428 pages
...within the triangle, at the other vertices are the opposite c A interior angles. [ZA and Z cj 108. THEOREM. An exterior angle of a triangle is equal to the sum of the opposite interior angles. Given: A ABC; exterior Z ABD. To Prove : Z ABU = ZA + Z C. Proof: Suppose BP to be drawn through B... | |
 | Louisiana. Department of Education - Education - 1908 - 366 pages
...it. one straight line intersect another straight line, the opposite angles are equal. 5. Prove that an exterior angle of a triangle is equal to the sum of their opposite interior angles. 6. Prove that if a straight line is perpendicular to one of two parallels,... | |
 | Webster Wells - Geometry, Plane - 1908 - 208 pages
...4. Since IIs AB and CE are cut by BC, 85. We have, from § 84, ^BCD = ^a + Z b = ^A + Z B. ^ Hence, an exterior angle of a triangle is equal to the sum of the two opposite interior angles. '- The following are immediate consequences of §§ 84, 85 : rP~86.... | |
 | Ernst Rudolph Breslich - Mathematics - 1909 - 402 pages
...and the angles. 10. Show that the sum of the interior angles of a triangle is 180°. 11. Show that an exterior angle of a triangle is equal to the sum of the two remote interior angles. 12. What is meant by a parallelogram ? 13. Prove that the opposite... | |
 | Herbert Ellsworth Slaught, Nels Johann Lennes - Geometry, Plane - 1910 - 304 pages
...propositions has been studied extensively during the last two centuries. RECTILINEAR FIGURES. 103. THEOREM. An exterior angle of a triangle is equal to the sum of the two opposite interior angles. The proof is left' to the student. Compare this theorem with that... | |
| |
The measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles. 
