 | Euclid, John Playfair - Euclid's Elements - 1846 - 334 pages
...interior angle ABC, with its adjacent exterior ABD, is equal (13. 1.) to two right angles ; therefore all the interior, together with all the exterior angles...figure, are equal to twice as many right angles as there are sides of the figure ; that is, by the foregoing corollary, they are D JJ equal to all the... | |
 | Euclides - 1846 - 292 pages
...%c. QEU 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... | |
 | Dennis M'Curdy - Geometry - 1846 - 168 pages
...(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... | |
 | Euclides - 1846 - 272 pages
...There are as many triangles constructed as the figure has sides, and therefore all these angles will be equal to twice as many right angles as the figure has sides (by Prop. 32) ; from these take four right angles, for the angles at the point F (by Cor. 3 Prop. 13),... | |
 | Education - 1847 - 508 pages
...SECTION I. — 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. 2. Equal triangles, upon equal bases in the same straight line, and towards the same parts, are between... | |
 | Charles William Hackley - Geometry - 1847 - 248 pages
...Hence it follows that the sum of all the inward angles of the polygon alone, A + B -f- C + D + E, is equal to twice as many right angles as the figure has sides, wanting the said four right angles. QED Corol. 1. In any quadrangle, the sum of all the four inward... | |
 | Anthony Nesbit - Plane trigonometry - 1847 - 492 pages
...accuracy of the previous work. Moreover, since the sum of all the interior angles of any polygon is equal to twice as many right angles as the figure has sides, lessened by four ; as the given figure has five sides, the sum of all its interior angles must be 2x5... | |
 | Euclides - 1848 - 52 pages
...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 sides. COB. 2. All the exterior angles of any rectilineal figure, made by producing the sides successively... | |
 | Euclid, Thomas Tate - 1849 - 120 pages
...interior angle A BC, with its adjacent exterior ABD, is equal (i. 13.) , to two right angles ; therefore all the interior, together with all the exterior angles...figure, are equal to twice as many right angles as there are sides of the figure; ^ * that is, by the foregoing corollary, they are \ four right angles;... | |
 | Elias Loomis - Conic sections - 1849 - 252 pages
...there are sides of the polygon BCDEF. Also, the angles of the polygon, together with four right angles, are equal to twice as many right angles as the figure has sides (Prop. XXVIII., BI); hence all the angles of the triangles are equal to all the angles of the polygon,... | |
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... twice as many right angles as the figure has sides. 
