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: For the Use of Schools - Page 81
by Nicholas Tillinghast - 1844 - 96 pages ## Annual Report of the Chief Superintendent of Education

1885 - 608 pages
...Show that the sum of the interior angles of any rectilineal figure together witli four right angles, is equal to twice as many right angles as the figure has sides. 5. Prove that the opposite sides and angles of a parallelogram are equal to one another, and that the... ## Cambridge University Examination Papers.Michaelmas Term,1884 to Easter Term ...

...straight line. 2. 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. 3. Equal triangles on the same base, and on the same side of it, are between the same parallels. If... ## The Elements of Geometry

Webster Wells - Geometry - 1886 - 392 pages
...angles is expressed by 2 R x (n — 2) , or 2 nR — 4 R. That is, the sum of the angles of a polygon is equal to twice as many right angles as the figure, has sides, less four right angles. PROPOSITION XLVII. THEOREM. 149. If the sides of a polygon are produced so as to form an exterior angle... ## Land and Marine Surveying in Reference to the Preparation of Plans for Roads ...

William Davis Haskoll - Hydrographic surveying - 1886 - 354 pages
...every station on a survey. In any polygon, regular or irregular, the sum of all the interior angles is equal to twice as many right angles as the figure has sides, less four right angles. As observed above, and as may be seen by referring to the figure 52, whether we consider the regular... ## First Steps in Geometry: A Series of Hints for the Solution of Geometrical ...

Richard Anthony Proctor - Geometry - 1887 - 202 pages
...produced to meet, the angles formed by these lines, together with eight right angles, are together equal to twice as many right angles as the figure has sides. 139. AP, BP, and CP are the internal bisectors of the angles of the triangle ABC. AP is produced to... ## A Treatise on Mine-surveying

Bennett Hooper Brough - Mine surveying - 1888 - 366 pages
...accuracy of the survey, as the interior angles of the polygon together with four right angles should be equal to twice as many right angles as the figure has sides. The interior angles of a traverse may be found from the bearings or courses by the following rules... ## Woolwich Mathematical Papers for Admission Into the Royal Military Academy ...

E. J. Brooksmith - Mathematics - 1889 - 354 pages
...right angles : that the sum of the angles of any rectilineal figure together with four right angles is equal to twice as many right angles as the figure has sides : and that the sum of the distances of any point from the angular points of the figure is greater than... ## The Elements of Plane and Solid Geometry: With Numerous Exercises

Edward Albert Bowser - Geometry - 1890 - 420 pages
...2 rt. Zs (n — 2) = 2n rt. Zs — 4 rt. Zs. Therefore, the sum of the angles of a polygon is also equal to twice as many right angles as the figure has sides, less four right angles. 149. COR. 2. The sum of the angles of a quadrilateral is equal to two right angles taken (4 — 2)... ## Elementary Psychology: With Practical Applications to Education and Conduct ...

James Hutchens Baker - Psychology - 1890 - 266 pages
...case of a particular polygon that the sum of its interior angles, together with four right angles, is equal to twice as many right angles as the figure has sides — and conclude that the law holds good of all polygons. In calculating the terms of a ' Mill's Logic,... 