 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.  Euclid - Page 66by Euclid, Rupert Deakin - 1903 - 164 pagesFull view - About this book
 | 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... | |
 | Euclides - 1838 - 264 pages
...ACB, are ti AX equal t to two right angles. Wherefore, if a side of a triangle, &c. o. E. i,. COn. 1. — All the interior angles of any rectilineal...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
...ACB, * i Ax. are also equal* to two right angles. Wherefore, if a side of a triangle, &c. QED COR. 1. All the interior angles of any rectilineal figure,...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
...and when the adjacent angles are equal to one another, each of them is a right angle (10. Def.). COR. 1. All the interior angles of any rectilineal figure,...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... | |
 | Nicholas Tillinghast - Geometry, Plane - 1844 - 110 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... | |
 | Euclides - 1845 - 546 pages
...equal to two right angles, (ax. 1.) Wherefore, if a side of any triangle be produced, &c. . QED COR. 1. All the interior angles of any rectilineal figure...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... | |
 | Euclid, James Thomson - Geometry - 1845 - 382 pages
...therefore also the angles CBA, BAC, ACB are equal to two right angles. Wherefore, if a side, &c. Cor. 1. All the interior angles of any rectilineal figure,...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... | |
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