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. Elements of Mechanical Drawing - Page 22by Gardner Chace Anthony - 1894 - 98 pagesFull view - About this book
| Charles Hutton - Mathematics - 1812
...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 - Mathematics - 1822 - 618 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 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 - Education - 1835 - 318 pages
...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 - Geometry - 1837 - 216 pages
...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 - Algebra - 1846 - 380 pages
...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 - Algebra - 1846 - 346 pages
...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... | |
| Benjamin Peirce - Geometry - 1847 - 150 pages
...perpendicular to its base, divides it, by § 57, into the two equal triangles ABC and ABG. 65. Theorem. **The sum of the three angles of any triangle is equal to two right angles.** Proof. Let ABC (fig. 36) be the given triangle. Produce AC to D, and draw CE parallel to AB. The angles... | |
| Elias Loomis - Algebra - 1855 - 352 pages
...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 - Geometry - 1860 - 472 pages
...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... | |
| Horatio Nelson Robinson - Geometry - 1868 - 276 pages
...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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