| Dionysius Lardner - Curves, Plane - 1840 - 314 pages
...supplement of its adjacent external angle, the internal and external angles, taken together, will be **equal to twice as many right angles as the figure has sides** ; but, from what has been already shown, the external angles alone are equal to four right angles.... | |
| Euclides - 1842
...triangles ; that is (2. Cor. 13. 1.), together with four right angles. Therefore all the angles of the **figure, together with four right angles, are equal...twice as many right angles as the figure has sides.** COR. 2. All the exterior angles of any rectilineal figure are together equal to four right angles.... | |
| John Playfair - Euclid's Elements - 1842 - 317 pages
...as the figure has sides ; but the exterior are equal to four right angles ; therefore the interior **are equal to twice as many right angles as the figure has sides,** wanting four. PROP. II. Two straight lines, which make with a third line the interior angles on the... | |
| Nicholas Tillinghast - Geometry, Plane - 1844 - 96 pages
...two regular polygons, having the same number of sides. The sum of all the angles in each figure is **equal to twice as many right angles as the figure has sides,** less four right angles (BI A{ Prop. 13), and as the number of sides is the same in each figure, the... | |
| Euclid - Geometry - 1845 - 199 pages
...angles CBA, BAC, ACB, are equal to two right angles. Wherefore, if a side of a triangle, &c. QED COB. **1. All the interior angles of any rectilineal figure,...twice as many right angles as the figure has sides.** the angles of these triangles are equal to twice as many right angles as there are triangles, that... | |
| Euclides - 1845
...triangles are equal to twice as many right angles as the figure has sides ; therefore all the angles of the **figure together with four right angles are equal to...twice as many right angles as the figure has sides.** COR. 2. All the exterior angles of any rectilineal figure, made by producing the sides successively... | |
| Nathan Scholfield - 1845
...two right angles, taken as many times, less two, as the polygon has sides (Prop. XXVIII.) ; that is, **equal to twice as many right angles as the figure has sides,** wanting four right angles. Hence, the interior angles plus four right angles, is equal to twice as... | |
| Euclides - 1846
...point F, that is, together with four right angles (1. 15, Cor. 2) : "Wherefore all the angles of the **figure, together with four right angles, are equal...twice as many right angles as the figure has sides.** COR. 2. All the exterior angles of any rectilineal figure are together equal to four right angles.... | |
| Dennis M'Curdy - Geometry - 1846 - 138 pages
...ax. 2 ! (4) p. 27; (c) p. 13. (e)p.29; Cor. 1. All the interior angles of any rectilineal figure and **four right angles, are equal to twice as many right angles as the figure has sides. For,** about a point within the figure, as many triangles may be formed as the figure has sides, each of whose... | |
| Euclides - 1846
...internal, are equal to twice as many right angles, as there are sides of the figure ; but the internal **with four right angles, are equal to twice as many right angles as** there are sides of the figure (by Cor. 6) ; take away from both the internal angles, and the external... | |
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