 | Edward Wells - Arithmetic - 1723 - 294 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 - 482 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... | |
 | John McGregor (teacher of mathematics.) - Mathematics - 1792 - 431 pages
...been accurately taken, adá all the inward angles into one fum ; and when the work is right, their fum is equal to twice as many right angles as the figure has fides, wanting 4 right angles, (Euclid 31.1. Cor. 1.) Or, inftead of the inward angles, their füpplements... | |
 | Mathematics - 1801 - 658 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... | |
 | John Playfair - Euclid's Elements - 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... | |
 | Robert Simson - Trigonometry - 1806 - 518 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... | |
 | Charles Hutton - Mathematics - 1807
...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... | |
 | Sir John Leslie - Geometry, Plane - 1809 - 522 pages
...is equal to two right angles. All the exterior angles therefore, added to the interior angles, ftre equal to twice as many right angles as the figure has sides. Consequently the exterior angles are equal to the four right angles which, by the last Proposition,... | |
 | John Dougall - 1810 - 554 pages
...each is one third part of two right angles, or two thirds of one right angle. PROP. VIII. fig. 21. The sum of all the interior angles of a polygon is equal to twice as many right angles, wanting four, as the figure has sides. Let the figure ABCDEF, be a polygon of six sides, that is, a... | |
 | Charles Hutton - Mathematics - 1811
...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,... | |
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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. 
