| Charles Hutton - Mathematics - 1812 - 620 pages
...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 - 616 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... | |
| Euclid, Dionysius Lardner - Euclid's Elements - 1828 - 542 pages
...thing, all the three, BAC, ABC, ACB, are together equal to two right angles ; hence in every triangle, the sum of its three angles is equal to two right angles.' It thus appears, that the theorem in question does not depend, when considered a priori, upon any series... | |
| Adrien Marie Legendre - Geometry - 1828 - 346 pages
...thing, all the three BAC, ABC, ACB are together equal to two right angles ; hence in every triangle, the sum of its three angles is equal to two right angles. It thus appears, that the theorem in question does not depend, when considered a priori, upon any series... | |
| John Radford Young - Geometry, Modern - 1833 - 238 pages
...thing, all the three, BAG, ABC, ACB, are together equal to two right angles ; hence, in every triangle, the sum of its three angles is equal to two right angles." This theorem is sufficient to remove the difficulty in the theory of parallels, as will be afterwards... | |
| 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.... | |
| Adrien Marie Legendre - Geometry - 1836 - 394 pages
...equal to two right angles. PROPOSITION XXV. THEOREM. In every triangle the sum of the three angles is equal to two right angles. Let ABC be any triangle : then will the an- R glc C + A + B be equal to two right angles. For, produce the side CA towards D, and... | |
| 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 - 376 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... | |
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