 | James Bates Thomson - Algebra - 1844 - 272 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 is' ' be demonstrated, either in common language, or by means of the signs... | |
 | Blaise Pascal - Apologetics - 1846 - 400 pages
...gradually arrived at the proof of the thirty-second proposition of the first book of Euclid : That the sum of the three angles of a triangle is equal to two right angles. Just at this moment, his father entered the apartment ; but so absorbed in thought was this... | |
 | Jeremiah Day - Algebra - 1847 - 358 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... | |
 | Jeremiah Day, James Bates Thomson - Algebra - 1848 - 264 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... | |
 | Charles Davies - Geometry - 1850 - 238 pages
...second, by Prob. VIII ; then will the angle HEF be equal to the third angle of the triangle. For, the sum of the three angles of a triangle is equal to two right angles (Bk. I. Th. xvii) ; and the sum of the three angles on the same side of the line DE is equal... | |
 | Charles Davies - Geometry - 1850 - 218 pages
...second, by Prob. VIII ; then will the angle HEF be equal to the third angle of the triangle. For, the sum of the three angles of a triangle is equal to two right angles (Bk. L Th. xvii) ; and the sum of the three angles on the same side of the line DE is equal... | |
 | Charles William Hackley - Trigonometry - 1851 - 524 pages
...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. Theorem 15), or 180° ; therefore subtracting the sum of the two given, 47° + 105°... | |
 | Samuel Griswold Goodrich - Children's literature - 1852 - 372 pages
...some property is asserted, and the truth of it required to be proved : thus when it is said that 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 hy geometry. A set, or collection, of... | |
 | Charles Davies - Geometry - 1886 - 340 pages
...second, by Prob- VIII ; then will the angle HEF be equal to the third angle of the triangleFor, the sum of the three angles of a triangle is equal to two right angles (Bk- I- Th- xvii) ; and the sum of the three angles on the same side of the line DE is equal... | |
 | Peter Nicholson - Cabinetwork - 1856 - 518 pages
...; but the sum of the two angles BAC, BAD, is equal to two right angles (theorem 1) ; therefore the sum of the three angles of a triangle is equal to two right angles. 80. COROLLARY 1. — If two angles of one triangle be equal to two angles of another triangle,... | |
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After remarking that the mathematician positively knows that the sum of the three angles of a triangle is equal to two right angles... 
