 | Edward Wells - Arithmetic - 1723 - 358 pages
...the Sum of all the Angles in all the Tri~ angles, into which the Figure is divided, will together be equal to twice as ma-ny right Angles, as the Figure has Sides. But the Angles about P, the inward Point of each Figure, wherein all the Triangles concur, are (by... | |
 | Thomas Malton - 1774 - 484 pages
...the Sides. ie equal to four Right Angles. And, all the internal Angles of any Right-lined Figure are equal to twice as many Right Angles as the Figure has Sides, wanting four, (Th. i. i0. i.) confequently, the external Angles being equal to thofe four (Th. 2. of... | |
 | Mathematics - 1801 - 656 pages
...;• add all the inward angles A, B, C, &c. together, and when the work is right, their sum will be equal to twice as many right angles, as the figure has sides, wanting four right angles. And when there is an angle, as F, that bends inward, and you measure the... | |
 | Robert Simson - Trigonometry - 1806 - 548 pages
...D, 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... | |
 | John Playfair - Mathematics - 1806 - 320 pages
...if a side of a triangle, &c. QED "7^ COR. 1. All the interior angles of any rectilineal figure are equal to twice as many right angles as the figure has sides, wanting four right angles. For any rectilineal figure ABCDE can be divided into as many triangles as... | |
 | Charles Hutton - Mathematics - 1807 - 460 pages
...work ; add all the inward angles A, B, c, &c, together ; for when the work is right, their sum will ba equal to twice as many right angles as the figure has sides, wanting 4 right angles. But when there is an angle, as F, that bends inwards, and you measure the external... | |
 | 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 - 592 pages
...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. Cor. 2. All the exterior angles of any rectilineal figure' are together equal to four right angles.... | |
 | John Playfair - Circle-squaring - 1819 - 348 pages
...all the angles of the figure, together with four right angles, that is, the angles of the figure are equal to twice as many right angles as the figure has sides, wanting four. COR. 2. All the exterior angles of any rectilineal figure are tegether equal to four... | |
 | Rev. John Allen - Astronomy - 1822 - 518 pages
...FC, FD, FE ; there are formed as many triangles as the figure has sides, all the angles of which are equal to twice as many right angles as the figure has sides [by this prop.] ; but of these all the angles about the point F are equal to four right angles [Ctor.... | |
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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. 
