 | Charles Hutton - 1812 - 620 σελίδες
...which 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 any triangle is equal to two right angles, this is a Theorem, the truth of which is demonstrated by Geometry. — A set or collection of such... | |
 | Charles Hutton - 1822 - 616 σελίδες
...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 any triangle is equal to two right angles, this is a Theorem, the truth of which is demonstrated by Geometry. — A set or collection of such... | |
 | American Institute of Instruction - 1835 - 318 σελίδες
...work, this author has pursued a different method in regard to parallel lines, by first proving that the sum of the three angles of any triangle is equal to two right angles ; but the demonstration is tedious and difficult for beginners, and is therefore rarely understood.... | |
 | Benjamin Peirce - 1837 - 216 σελίδες
...being perpendicular to its base, divides it, by art. 57, into the two equal triangles ABC and ABG. 64. Theorem. The sum of the three angles of any triangle is equal to two right angles. Demonstration. Let ABC (fig. 36) be the given triangle. Produce AC to D, and draw CE parallel to AB.... | |
 | Elias Loomis - 1846 - 380 σελίδες
...statement of some property, the truth of which is required to be proved. Thus when it is said that the sum of the three angles of any triangle is equal to two right angles, this is a theorem, the truth of which is demonstrated by Geometry. (8.) A. problem is a question requiring... | |
 | Elias Loomis - 1846 - 376 σελίδες
...statement of some property, the truth of which is required to be proved. Thus when it is said that the sum of the three angles of any triangle is equal to two right angles, this is a theorem, the truth of which is demonstrated by Geometry. (8.) A problem is a question requiring... | |
 | Elias Loomis - 1855 - 356 σελίδες
...the statement of some property, the truth of which is required to be proved. Thus the principle that the sum of the three angles of any triangle is equal to two right angles, is a theorem, the truth of which is demonstrated by Geometry. (8.) A problem is a question requiring... | |
 | Horatio Nelson Robinson - 1860 - 470 σελίδες
...the theorem ; the sum of the angles of any parallelogram it eoual tc four right angles. THEOREM XI. The sum of the three angles of any triangle is equal to two right angles. Let AB C be a triangle, and through its vertex C / draw a line parallel to the b\e/a base AB, and produce... | |
 | Benjamin Peirce - 1868 - 200 σελίδες
...the Angles of a Triangle. But BDC>ADC, while ACD>BCD; whence BDC> BCD, so that in the triangle BCD, by § 62, we have BC>BD. 64. Theorem. Two right triangles...Produce AC to D, and draw CE parallel to AB. The angles AliC and BCE, being alternate-internal angles, are equal, and BAC and ECD, being externalinternal angles,... | |
 | Horatio Nelson Robinson - 1868 - 276 σελίδες
...the theorem ; the sum of the angles of any parallelogram it toual k four right angles. THEOREM XI. The sum of the three angles of any triangle is equal to two right angles. Let AB O be a triangle, and through its vertex C draw a line parallel to the base AB, and produce the... | |
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The sum of the three angles of any triangle is equal to two right angles. 
