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. Elements of Plane Geometry - Page 46
by Thomas Hunter - 1878 - 132 pages ## A Course of Mathematics ...: Composed for the Use of the Royal Military ...

Charles Hutton - Mathematics - 1811 - 442 pages
...work ; add all the inward angles A, B, c, &C, together ; for when the work is right, their sum will be 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... ## A Course of Mathematics: For the Use of Academies as Well as Private Tuition

Charles Hutton - Mathematics - 1812 - 620 pages
...or intvard angles, as the figure has sides : therefore the sum of all the inward and outward angles, is equal to twice as many right angles as the figure has sides. But the sum of all the inward angles, with four right angles, is equal to twice as many right angles... ## A Course of Mathematics: In Two Volumes : for the Use of Academies ..., Volume 1

Charles Hutton - Mathematics - 1816 - 610 pages
...former sum. Hence it follows thai the sum of .ill the inward angles of the polygon alone, A + B+C+D + E, is equal to twice as many right angles as the figure has skies, wanting the said four right angles, q. ED THEOREM XX. WHEN every Side of any Figure is produced... ## The Elements of Euclid: Viz. the First Six Books, Together with the Eleventh ...

Euclides - 1816 - 588 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.... ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

John Playfair - Circle-squaring - 1819 - 350 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... ## A Course of Mathematics: For the Use of Academies, as Well as Private ...

Charles Hutton - Mathematics - 1822 - 616 pages
...or inward angles, as the figure IMS sides : therefore the sum of all the inward and outward angles, is equal to twice as many right angles as the figure has sides. But the sum of all the inward angles, with four right angles, is equal to twice as many right angles... ## Elements of Geometry and Trigonometry: With Notes

Adrien Marie Legendre - Geometry - 1822 - 394 pages
...equal to the angle B, and the other part DAE is equal to the angle C. PROPOSITION XXVIII. THEOREM. The sum of all the interior angles of a polygon is equal to as many times two right angles, as there are units in the number of sides diminished by two. and, in... ## The First Six Books with Notes

Euclid - 1822 - 222 pages
...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... ## Euclid's Elements of Geometry: The Six First Books. To which are Added ...

Rev. John Allen - Astronomy - 1822 - 516 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.... 