| Pierre Simon marquis de Laplace, Thomas Young - Celestial mechanics - 1821 - 344 pages
...ut pleasure, AB, meeting BC in B, \ j) and make Z.BAD=ABC (101), then AD||CB ~ CB 108. THEOREM. The **angles of any triangle, taken together, are equal to two right angles.** Produce AB to C, and draw BD parallel to AE. ED Then Z.EBD=AEB (106), and /LDBC=EAB; therefore the... | |
| George Darley - 1828 - 169 pages
...form, in which ABC represents the cliff with its " summit/' C, " beetling" over the base at B. ABT. **37. " The three internal angles of any triangle taken together, are equal to two right angles."** From this theorem we perceive that, of whatever shape or size a plane rectilineal triangle may be,... | |
| Euclides - 1833
...triangle be produced, the external angle is equal to the sum of the two internal and opposite angles; and **the three internal angles of any triangle taken together, are equal to two right angles.** Draw througli the external angle, a line parallel to the side, not conterminous with the produced part,... | |
| George Darley - Geometry - 1836 - 128 pages
...than either of the two farther internal angles. This is immediately evident from the last Article. **ART. 37. The three internal angles of any triangle taken together, are equal to two right angles.** In the triangle ABC, the angles ABC, BCA, CAB, taken together, are equal to two right angles. DEM.... | |
| Frederick Augustus Griffiths - 1839
...triangle has one of its angles obtuse. An acute angled triangle has one of its angles acute. The three **angles of any triangle taken together are equal to two right angles,** or 180°. The difference of the squares of two sides of a triangle is equal to the product of their... | |
| Frederick Augustus Griffiths - Artillery - 1859 - 354 pages
...triangle has one of its angles obtuse. An acute-angled triangle has all its angles acute. The three **angles of any triangle, taken together, are equal to two right angles,** or 180°. The difference of the squares of two sides of a triangle is equal to the product of their... | |
| Alexander Mackenzie
...proportionals, and, perhaps, this is the reason why he adopts the term tripartite. Now, we know that the three **angles of any triangle, taken together, are equal to two right angles** ; and that, two angles being given, we know the remaining angle ; or, one angle being given, we know... | |
| Alexander Mackenzie, Alexander Macgregor, Alexander Macbain - Scotland - 1883
...proportionals, and, perhaps, this is the reason why he adopts the term tripartite. Now, we know that the three **angles of any triangle, taken together, are equal to two right angles;** and that, two angles being given, we know the remaining angle ; or, one angle being given, we know... | |
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