| Charles Hutton - Mathematics - 1811 - 406 pages
...triangles, is equal to two right angles (th. 17); therefore the sum of the angles of all the triangles is **equal to twice as many right angles as the figure has sides.** But the sum of all the angles about the point P, which are so many many of the angles of the triangles,... | |
| Euclides - 1816 - 588 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... | |
| John Playfair - 1819 - 354 pages
...have any number of sides, the proposition is demonstrated just as in the case of a triangle. Therefore **all the exterior angles of any rectilineal figure are together equal to four right angles.** QED COR. 1. Hence, all the interior angles of any triangle are equal to two right angles. For all the... | |
| John Playfair - Circle-squaring - 1819 - 350 pages
...angles as there are triangles (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 (cor. 1. 32. 1.) ; therefore... | |
| Euclid, Robert Simson - Geometry - 1821 - 514 pages
...angles. Wherefore if a side of a triangle, &c. QED COK. 1. All the interior aigles of any rectilineal **figure, together with four right angles, are equal to twice as many right** E' angles as the figure has sides. For any rectilineal figure ABCDE can be divided into as many triangles... | |
| Euclid - 1822 - 222 pages
...therefore equal to B AE and EAC. Cor. 6. All the internal angles of any rectilineal figure, ABCDE, **together with four right angles, are equal to twice as many right angles as the figure has sides.** Take any point F within the figure and draw the right lines FA, FB, FC, FD, and FE. There are formed... | |
| Rev. John Allen - Astronomy - 1822 - 508 pages
...as many right angles, except four, as the figure has sides ; and all tbe angles of these triangles **are equal to twice as many right angles as the figure has sides** (32. 1 /CM.), therefore the angles of these triangles which are at their common vertex A, being those... | |
| Charles Hutton - Mathematics - 1822 - 616 pages
...triangles, is equal to two right angles (th. 17) ; therefore the sum of the angles of all the triangles is **equal to twice as many right angles as the figure has sides.** But the sum of all the angles about the point p, which are so / many of the angles of the triangles,... | |
| Rev. John Allen - Astronomy - 1822 - 516 pages
...two right angles [13. 1} ; therefore all the exterior and interior angles of the figure are together **equal to twice as many right angles as the figure has sides** ; but the interior angles are equal to twice as many right angles, except four, as the figure has sides... | |
| Edward Riddle - Nautical astronomy - 1824 - 572 pages
...twice as many right angles as the figure has sides ; or the interior angles of the figure, themselves, **are equal to twice as many right angles as the figure has sides,** wanting four right angles. QED Cor. 1. All the interior angles of any quadrilateral figure are together... | |
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