 | Olinthus Gregory - 1863 - 482 σελίδες
...out ; the external angle A c D will be equal to the two internal opposite angles A B. " cn 2. In any triangle, the sum of the three angles is equal to two right angles. Cor. 1. If two angles in one triangle be equal to two angles in another : the third will also be equal... | |
 | James Pyle Wickersham - 1865 - 504 σελίδες
...straight lines intersect each other, the opposite or vertical angles, which they form, are equal;" u ln every triangle the sum of the three angles is equal to two right angles;" "Every triangle is half the parallelogram which has the same base and the same altitude;" "The square... | |
 | 1884 - 460 σελίδες
...for all. If expressed, however, it would be something like this : " We have now shown that in this triangle the sum of the three angles is equal to two right angles ; but that is nothing peculiar or characteristic of the triangle before us, and it is therefore true... | |
 | Edward Brooks - 1868 - 284 σελίδες
...are contrary to the hypothesis; hence, ABC must be greater than CAB. Therefore, etc. THEOREM XIII. In every triangle the sum of the three angles is equal to two right angles. c Let ABC be a triangle; then will S\ , the sum of its three angles, A, B,C, be equal to two right... | |
 | Benjamin Greenleaf - 1868 - 340 σελίδες
...the two interior and opposite angles CAB, ABC (Art. 34, Ax. 2). PROPOSITION XXVIII. — THEOREM. 95. In every triangle the sum of the three angles is equal to two right angles. Let ABC be any triangle ; then will, the sum of the angles ABC, BCA, CAB be equal to two right angles.... | |
 | Lefébure de Fourcy (M., Louis Etienne) - 1868 - 350 σελίδες
...triangles can be formed, which will be similar to each other, but not equal. It is always understood that the sum of the three angles is equal to two right angles. 2. Geometry furnishes very simple constructions for determining a triangle, by means of some of its... | |
 | Charles Davies, Adrien Marie Legendre - 1869 - 470 σελίδες
...XX., C. 2): hence, GHK is equal to AB C ; which was to be proved. PROPOSITION XXV. THEOREM. In any triangle, the sum of the three angles is equal to two right angles. Let CBA be any triangle : then will the sum of the angles C, A, and B, be equal to two right angles^... | |
 | Charles Davies - 1872 - 464 σελίδες
...angle HMB is equal to its alternate angle MBC (P. XX., C. 2) : hence, PROPOSITION XXV. THEOREM. In any triangle, the sum of the three angles is equal to two right angles. Let CBA be any triangle: then will the sum of tLe angles C, A, and B, be equal to two right angles.... | |
 | Aaron Schuyler - 1876 - 384 σελίδες
...the angles of a given triangle. 5. Circumscribe a circle about a triangle, and prove by (153) that the sum of the three angles is equal to two right angles. 6. Prove by (127), (153), that the greatest angle of a triangle is opposite the greatest side ; that,... | |
 | Wonders - 1877 - 140 σελίδες
...TSE formed by the Earth, the Sun, and the star; when the Earth is at T', we measure the angle S T' E. In every triangle the sum of the three angles is equal to two right angles, — that is to say, to 180° ; then, if we make the sum of the two observed angles, STE and S T' E,... | |
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In every triangle the sum of the three angles is equal to two right angles. 
