 | Andrew Bell - Euclid's Elements - 1837 - 290 pages
...CBA, BAC, ACB, are equal to two right angles. 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 be divided into as many triangles as the figure has sides, by drawing straight lines from a point F... | |
 | 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... | |
 | 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... | |
 | 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... | |
 | Euclid, James Thomson - Geometry - 1837 - 410 pages
...° there are triangles ; that is, as there are sides in the figure BCDEF; and that (I. 32. cor. 1.) all the angles of the figure, together with four right angles, are likewise equal to twice as many right angles as there are sides in the figure ; therefore all the angles... | |
 | Euclides - 1838 - 264 pages
...the common vertex of «2cor is i "le triangles; that is,* together with four right angles. Therefore all the angles of the figure, together with four right...twice as many right angles as the figure has sides. COB. 2. — All the exterior angles of any rectilineal figure are together equal to four right angles.... | |
 | 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
...angles. 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...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
...as there are triangles (Euc. 32. 1.); that is, as there are sides in the figure BCDEF; and because all the angles of the figure, together with four right angles, are likewise equal to twice as many right angles as there are sides in the figure (Euc. 1. Cor. 32. 1.);... | |
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F, which is the common vertex of the triangles: that is », together with four right angles. 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. 
