| Charles Reiner - Geometry - 1837 - 254 pages
...vertex of these triangles = 4 rt. /.s; therefore, the sum 01 the interior angles of any polygon is equal to twice as many right angles as the figure has sides less [minus] four. M.—If the number of sides be three, four, five, six, seven, &c., what is the sum... | |
| Adrien Marie Legendre - Geometry - 1837 - 376 pages
...two right angles, taken as many times, less two, as the polygon has sides (Prop. XXVI.) ; 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... | |
| Commissioners of National Education in Ireland - Measurement - 1837 - 284 pages
...you go along, as also the angles. angles, A, B, C, &c. of the figure together, and their sum must be equal to twice as many right angles as the figure has sides, wanting four right angles. But when the figure has a re-enterant angle, as F, measure the external... | |
| Euclides - 1838 - 264 pages
...a side of a triangle, &c. o. E. i,. COn. 1. — All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. For any rectilineal figure, ABCDE, can be divided into as many triangles as the figure has sides, by... | |
| Euclides - 1840 - 192 pages
...two right angles. All the angles, therefore, of the triangles into which the AE figure is divided, are equal to twice as many right angles as the figure has sides. But of these, the angles round the point F are equal to four right angles (Prop. 13, cor.) : if these... | |
| Dionysius Lardner - Curves, Plane - 1840 - 386 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 - Geometry - 1841 - 378 pages
...Wherefore, if a side of a triangle, &c. QED COR. 1. All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. For any rectilineal figure ABCDE can be divided into as many triangles as the figure has sides, by... | |
| Euclides - 1842 - 316 pages
...each of them is a right angle (10. Def.). COR. 1. All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. For any rectilineal figure ABCDE can be divided into as many triangles as the figure has sides, by... | |
| John Playfair - Euclid's Elements - 1842 - 332 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... | |
| Education - 1844 - 688 pages
...angles on the same side together equal to two right angles, the two straight lines shall be parallel. 5. If the square described upon one of the sides of a triangle be equal to the squares described upon the other two sides of it, the angle contained by these two... | |
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