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 ## Mathematics, mechanics, heat

...triangle are known, the third can be formed by subtracting their sum from two right angles. Corollary VI. An exterior angle of a triangle is equal to the sum of the two opposite interior angles, as angle BCD = angle A + angle B. THEOREM XVII. 77. If two triangles have two sides and the included... ## Annual Register of the United States Naval Academy, Annapolis, Md, Volumes 60-64

United States Naval Academy - 1904 - 980 pages
....^^^«(tO.-u (b) Given л- + xy = 70 and xy — y* =12, find .т and y. GEOMETRY. I. (a) Prove that an exterior angle of a triangle is equal to the sum of the two opposite interior angles. Define axiom and postulate, and give an example of each. Define trapezoid, trapezium, rhombus, and... ## Plane Geometry

Fletcher Durell - Geometry, Plane - 1904 - 382 pages
...its equal, ZA.and for /.BCE its equal, ZB, Ax. 8. ZA + /.B + /.BCA = 2 rt. A. 0. E. J>. 135. COR. 1. An exterior angle of a triangle is equal to the sum of the two opposite interior angles. 136. COR. 2. The sum of any two angles of a triangle is less than two right angles. 138. COR. 4. A... ## Plane and Solid Geometry

George Albert Wentworth - Geometry - 1904 - 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... ## Plane and Solid Geometry

Fletcher Durell - Geometry - 1911 - 553 pages
...LECD its equal, Z.4,and for LBCE its equal, LB, Ax. 8, /A+ ZB + Z BGA - 2 rt. Z . 0- EB 135o Con. 1. An exterior angle of a triangle is equal to the sum of the two opposite interior angles. 136o COR. 2. The sum of any two angles of a triangle is less than two right angles. 138. COR. 4. A... ## Syllabus of Plane Geometry: (corresponding to Euclid, Book I-VI) ; Prepared ...

Cora Lenore Williams - Geometry - 1905 - 122 pages
...Theor. J. Straight lines parallel to the same straight line are parallel to each other.* Prop. 70. Any exterior angle of a triangle is equal to the sum of the two opposite interior angles, and the sum of the three interior angles is equal to two right angles. Prop. 71. The acute angles of... ## Plane Geometry Suggestive Method

George Clinton Shutts - 1905 - 260 pages
...perimeter of a triangle is less than twice the sum of the medians. PROPOSITION XXVIII. 119, Theorem. An exterior angle of a triangle is equal to the sum of the opposite interior angles. Let ABC represent a triangle, D AC an erterior angle, and B and C the... ## Artillery Notes..., Issues 26-31

Coast Artillery School (U.S.) - 1906 - 440 pages
.../—The determination of these circles depends on the two following propositions of geometry: namely, the exterior angle of a triangle is equal to the sum of the two opposite interior angles; and, secondly, an inscribed angle is measured by one-half the arc intercepted between its sides. Thus,... ## Handbook of Mathematics for Engineers and Engineering Students

Joseph Claudel - Mathematics - 1906 - 758 pages
...acute angles of a right triangle are complementary (617, 633). 653. The exterior angle CBD (Fig. 41) of a triangle is equal to the sum of the two opposite interior angles A and C, and consequently greater than either of them. When the successive sides of a polygon are prolonged... 