Books Books 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. Euclid's Elements of Geometry: The First Six, the Eleventh and Twelfth Books - Page 56
by Euclid - 1765 - 464 pages ## Modern Methods in Elementary Geometry

E. M. Reynolds - Geometry - 1868 - 112 pages
...angles are together equal to twice as many right "angles as the figure has sides. , Hence the interior angles are equal to twice as many right angles as the figure has sides, diminished by four right angles. COR. The exterior angle of any regular polygon of n sides is... ## Annual Report of the Commissioners ..., Volume 36

1870
...hours a day. Geometry and Mensuration. — 1. Show that 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. (12 marks). 2. Enunciate and prove the 32nd proposition of the First Book of Euclid's Elements.... ## On Intelligence

Hippolyte Taine - Knowledge - 1871 - 542 pages
...together equal to four right angles ; hence it follows that the polygon contains a number of angles which, together with four right angles, are equal to twice as many right angles as there are sides. — Here the explanatory intermediate is a character comprised in all the elements... ## Elements of Geometry, Conic Sections, and Plane Trigonometry

Elias Loomis - Geometry - 1871 - 58 pages
...F, that is, together with four right angles (Prop. V., Cor. 2). Therefore the angles of the polygon are equal to twice as many right angles as the figure has sides, wanting four right angles. Cor. 1. The sum of the angles of a quadrilateral is foui right angles... ## Euclid's Elements of Geometry

Euclid - Geometry - 1872 - 261 pages
...internal, are equal to twice as many right angles as there are sides of the figure ; but the internal with four right angles, are equal to twice as many right angles as there are sides of the figure (by Cor. 6) ; take away from both the internal angles, and, the external... ## The Acting Teacher's and Student's in Training Guide and Text Book for ...

Henry Major - Student teachers - 1873
...triangles; that is, together with four right angles. Therefore all the angles of the figure, together witb four right angles, are equal to twice as many right angles as the figure has sides. XXXIII. — The straight lines which join the extremities of two equal and parallel straight... ## Elementary Mathematics: Embracing Arithmetic Geometry, and Algebra

Lewis Sergeant - 1873
...angles (Prop. 9). Proposition 32.— Theorem. The inner angles of a rectilinear figure, with four riyht angles, are equal to twice as many right angles as the figure lMS sides. The figure may be divided into as p many triangles as it has sides, by joining the angular... ## A School Euclid. Being Books I.&II. of Euclid's Elements. With Notes ...

Euclides - 1874
...equal to four right angles. Therefore, &c. COROLLARY 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. n For any interior angle ABD, together with its *3 • adjacent exterior angle DBC is equal... ## The Elements of Euclid, containing the first six books, with a selection of ...

Euclides - 1874
...triangles are equal to twice as many right angles as the figure has sides ; 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, made by producing the sides successively... 