Books Books 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. A Course of Mathematics ...: Composed for the Use of the Royal Military ... - Page 66
by Charles Hutton - 1811 ## A Popular Course of Pure and Mixed Mathematics ...: With Tables of ...

Peter Nicholson - Mathematics - 1825 - 372 pages
...I). Cor. 1 . All the interior angles of any rectilínea] 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... ## Elements of Arithmetic, Algebra, and Geometry

George Lees - 1826
...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. PROP. XIII. THEOREM. If two triangles, BAG, EOF, have two angles, BAG, ABC, and a side AC in... ## The Elements of Euclid: The Errors by which Theon, Or Others, Have Long ...

Robert Simson - Trigonometry - 1827 - 513 pages
...zi. 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... ## Elements of Geometry: With Notes

John Radford Young - Euclid's Elements - 1827 - 208 pages
...in each triangle amounts to two right angles, therefore the angles of all the triangles are together equal to twice as many right angles as the figure has sides, that is to say, the sum of the angles of the polygon, together with those about the point within it,... ## Elements of the Geometry of Planes and Solids: With Four Plates

Ferdinand Rudolph Hassler - Electronic book - 1828 - 159 pages
...all the angles of the triangles, there remain all the angles of the poligon, their sum will therefore be equal to twice as many right angles as the figure has sides wanting these four right angles; as was to be demonstrated. Carol. 1. When all the sides or all the angles... ## The First Six Books of the Elements of Euclid, with a Commentary and ...

Euclid, Dionysius Lardner - Euclid's Elements - 1828 - 324 pages
...right angles as the figure has sides ; but the internal angles, together with four right angles, are equal to twice as many right angles as the figure has sides (134). Take from both, the internal angles and the external remain equal to four right angles. %* This... ## The London Encyclopaedia: Or, Universal Dictionary of Science ..., Volume 10

...exterior angle being equal to two right angles (Theorem VI.), all the interior and exterior angles will be equal to twice as many right angles as the figure has sides, or equal to the interior angles and four right angles ; therefore the exterior angles are equal to... ## The London encyclopaedia, or, Universal dictionary of science ..., Volume 10

Thomas Curtis (of Grove house sch, Islington)
...u_. 118 119 m.iti) right angles as the figure has sides. Hence (he interior angles of the figure are equal to twice as many right angles as the figure has sides wanting four right angles. Car. I. All the interior angle* of a quadrilateral figure are together equal to... ## Elements of Geometry: Being Chiefly a Selection from Playfair's Geometry

John Playfair - Geometry - 1829 - 186 pages
...xr = (n— 2) x 2r, that is, all the interior angles of any convex rectilineal figure are together equal to twice as many right angles as the figure has sides less two sides. " Es. PROPOSITION M. THEOREM. All the exterior angles of any convex rectilineal figure,... 