 | Euclid, Dionysius Lardner - Euclid's Elements - 1828 - 542 pages
...angles. Hence it follows, that the sum of all the angles internal and external, including the reentrant angles, is equal to twice as many right angles as the figure has sides, together with the excess of every reentrant angle above two right angles. But (134) the sum of the... | |
 | Ferdinand Rudolph Hassler - Geometry - 1828 - 180 pages
...two right angles. § 28. THEOREM. In any rectilineal figure the sum of all the inner angles together is equal to twice as many right angles as the figure has sides, wanting four right angles. APPLIC. In the rectilineal figure ABDEFG, (fig. 34,) the sum of all the... | |
 | Thomas Curtis - Aeronautics - 1829 - 814 pages
...118 119 липу right angles as the figure has sides. Hence the interior angles of the figure are equal to twice as many right angles as the figure has sides wanting four right angles. Cor. 1. All the interior angles of a quadrilateral figure are together equal... | |
 | John Playfair - Geometry - 1829 - 210 pages
...diagonals &c. QED PROPOSITION L. THEOREM. All the interior angles of any rectilineal figure arc together equal to twice as many right angles as the figure has sides, wanting four right angles'. Let ABCDE be any rectilineal figure; all its interior angles A, B, C, D,... | |
 | Pierce Morton - Geometry - 1830 - 584 pages
...producing its sides) are together equal to four right angles ; and the sum of its interior angles, together with four right angles, is equal to twice as many right angles as the figure has sides . . • 15 (¿•) The area of a rectilineal figure may be obtained by dividing it into triangles,... | |
 | John Radford Young - Geometry, Modern - 1833 - 238 pages
...single interior opposite angle CDE. A — PROPOSITION XVII. THEOREM. In any polygon the sum of all the angles is equal to twice as many right angles as the figure has sides, all brtfour right angles. For if from the vertices of the several angles, lines be drawn to any point... | |
 | Euclid - Euclid's Elements - 1833 - 216 pages
...the angle EDN ; therefore the reentrant angle, with the sum of all the other internal and external angles, is equal to twice as many right angles as the figure has sides, and to its excess EDN above two right angles : but the internal angles, with four right angles, are... | |
 | Thomas Perronet Thompson - Euclid's Elements - 1833 - 168 pages
...severally capable of being so divided. And because the interior angles of each of such smaller figures are equal to twice as many right angles as the figure has sides, diminished by four right angles, (or, which is the same thing, to twice as many right angles as the... | |
 | Charles Bonnycastle - Geometry - 1834 - 670 pages
...expressed as the following proposition : "The interior angles of any closed plane figure are together equal to twice as many right angles as the figure has sides, minus four right angles." 206. And as a second application of the principle in question, or, which... | |
 | Mathematics - 1835 - 684 pages
...producing its sides) are together equal to four right angles ; and the sum of its interior angles, together with four right angles, is equal to twice as many right angles as the figure has sides . . . 15 (c) The area of a rectilineal figure may be obtained by dividing it into triangles, having... | |
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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. 
