Books Books An exterior angle of a triangle is equal to the sum of the two opposite interior angles. Junior High School Mathematics ... - Page 29
by Edson Homer Taylor, Fiske Allen - 1923 ## Plane Geometry

George Albert Wentworth - Geometry, Plane - 1899 - 272 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. Tlie sum of two sides of... ## The Essentials of Geometry

Webster Wells - Geometry - 1899 - 420 pages
...Cor. I. It follows from the above demonstration that Z BCD = Z ECD + Z J3OS = Z .4 + Z 5 ; 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. RECTILINEAR... ## Plane Geometry

William James Milne - Geometry, Modern - 1899 - 258 pages
...acute angle of one are equal to a side and an acute angle of the ot^er, each to each. 115. Cor. V. Any exterior angle of a triangle is equal to the sum of the two opposite interior angles. 1. What interior angle is equal to Z t' ? Why ? 2. What interior angle is equal to Z s' ? Why ? 3.... ## The Essentials of Geometry

Webster Wells - Geometry - 1899 - 450 pages
...85. Cor. I. It follows from the above demonstration that ZBCD = ZECD + ZBCE = ZA + ZB; hence 1. .471 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.... ## Plane and Solid Geometry

William James Milne - Geometry - 1899 - 404 pages
...angle of one are equal to a side and an acute angle of the ofoer, each to each. " 115. Cor. V. Any exterior angle of a triangle is equal to the sum of the two opposite interior angles. 1. What interior angle is equal to Z t' ? Why ? 2. What interior angle is equal to Z s' ? Why ? 3.... ## Plane Geometry

Edward Brooks - 1901 - 278 pages
...angle of the other, the other acute angles are equal. TRIANGLES. PROPOSITION XVIII. — THEOREM. The exterior angle of a triangle is equal to the sum of the two opposite interior angles. Given. — Let ABC be any triangle, and CBD be its exterior angle. To Prove. — Then we are to prove... ## Plane Geometry

Arthur Schultze - 1901 - 260 pages
...equal respectively to the hypotenuse and an acute angle of the other. PROPOSITION XIII. THEOREM 100. An exterior angle of a triangle is equal to the sum of the two remote interior angles. f / B CD Hyp. Z ACD is an exterior angle of A ABG. To prove Z ACD =... ## Plane and Solid Geometry

Arthur Schultze, Frank Louis Sevenoak - Geometry - 1901 - 396 pages
...92. The altitudes upon the arms of an isosceles triangle are equal. PROPOSITION XIII. THEOREM 100. An exterior angle of a triangle is equal to the sum of the two remote interior angles. , B • CD Hyp. ZACD is an exterior angle of A ABC. To prove Z ACD... ## Plane and Solid Geometry

Arthur Schultze, Frank Louis Sevenoak - Geometry - 1902 - 390 pages
...equal respectively to the hypotenuse and an acute angle of the other. PROPOSITION XIII. THEOREM 100. An exterior angle of a triangle is equal to the sum of the two remote interior cuujles. BGD Hyp. Z ACD is an exterior angle of A ABC. To prove Z ACD = ZA... 