 | John Playfair - Euclid's Elements - 1835 - 336 pages
...together ; or, two quantities that are each of them equal to a third quantity, are equal to each other. 5. A Theorem is a demonstrative proposition ; in which...when it is said that the sum of the three angles of any plane triangle is equal to two right angles, this is called a Theorem ; and the method of collecting... | |
 | John Playfair - Euclid's Elements - 1837 - 332 pages
...or, two quantities that are each of them equal to a third quantity, are equal to each other. ,. if 5. A Theorem is a demonstrative proposition ; in which...when it is said that the sum of the three angles of any plane triangle is equal to two right angles, this is called.a Theorem ; and the method of collecting... | |
 | Charles William Hackley - Trigonometry - 1838 - 328 pages
...to 47°, and the other equal to 105° 30', it will be easy to find the third angle, by recollecting that the sum of the three angles of a triangle is equal to two right angles (Geom. B. 1, Prop. 25,) or 180° ; therefore subtracting the sum of the two given, 47° + 105°... | |
 | Dionysius Lardner - Curves, Plane - 1840 - 386 pages
...of the adjacent internal angle. (51.) The following consequences flow obviously from the principle, that the sum of the three angles of a triangle is equal to 180° : — (52.) If one angle of a triangle is right, the sum of the other two is equal to a right... | |
 | John Joseph Griffin - Crystallography - 1841 - 548 pages
...in any right-angled triangle, a either n or w be given, then n, c and w are all given ; because the sum of the three angles of a triangle is equal to two right angles. Hence: c = 90°; n = 00° — w ; and w = <JO° — • n. No. tiiven. Sought. Equations. Logarithmic... | |
 | John Joseph Griffin - Crystallography - 1841 - 538 pages
...in any right-angled triangle, either n or w. be given, then n, с and w are all given; because the sum of the three angles of a triangle is equal to two right angles. Hence: с = 90°; n = 90° — w ; and w = 90° — n. Т E.) OBLIQUE-ANGLED PLANE TRIANGLES.... | |
 | John Playfair - Euclid's Elements - 1842 - 332 pages
...together ; or, two quantities that are each of them equal to a third quantity, are equal to each other. 5. A Theorem is a demonstrative proposition ; in which...when it is said that the sum of the three angles of any plane triangle is equal to two right angles, this is called a Theorem; and the method of collecting... | |
 | James Bates Thomson - Algebra - 1844 - 266 pages
...equations, though they may not be presented to us under the algebraic forms. Thus the proposition, that the sum of the three angles of a triangle is equal to two right angles, (Euc. 32. 1,) may be demonstrated, either in common language, or by means of the signs used... | |
 | Nicholas Tillinghast - Geometry, Plane - 1844 - 110 pages
...is the sum of the two angles CBE, EBD, is equal to the sum of the two angles BAC, BCA. Cor. 1 . The sum of the three angles of a triangle is equal to two right angles ; for CBD-f-CBA is equal to two right angles (Prop. 1) ; now we have just seen that CBD is equal... | |
 | Euclid, John Playfair - Euclid's Elements - 1846 - 334 pages
...together ; or, two quantities that are each of them equal to a third quantity, are equal to each other. 5. A Theorem is a demonstrative proposition ; in which...when it is said that the sum of the three angles of any plane triangle is equal to two right angles, this is called a Theorem; and the method of collecting... | |
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... the sum of the three angles of a triangle is equal to two right angles, that is a theorem, the truth of which is demonstrated by geometry. 
