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 sidef. For any rectilineal figure ABCDE can be divided into as many triangles as the figure has sides, by drawing... Elements of geometry: consisting of the first four,and the sixth, books of ... - Page 30
by Euclides - 1842 ## Interim Report of the Commissioners on Certain Parts of Primary Education ...

...that LP ie less than LM. 3. Prove that the sum of the interior angles of any rectilineal figure is equal to twice as many right angles as the figure has sides, dimished by four right angles. ABC is an equilateral triangle in which AD is drawn perpendicular to... ## The Colliery Manager's Handbook

Caleb Pamely - 1904 - 1238 pages
...tested by Euclid, for, " The sum of all the interior angles of any rectilinear figure, together with 4 right angles, are equal to twice as many right angles as the figure has sides." This is not so thorough a test as the plotting, because it checks only the angles taken and not the... ## A Text-book of Euclid's Elements for the Use of Schools, Book 1

Euclid - Euclid's Elements - 1904 - 488 pages
...angles at F, which are equal to four right angles. I. 15, Cor. Therefore all the interior angles of the figure, together with four right angles, are equal to twice as many right COROLLARY 2. If the sides of a rectilineal figure, which has no re-entrant angle, are produced in order,... ## A Treatise on Surveying, Volume 1

Reginald Empson Middleton - Surveying - 1904 - 332 pages
...angles as the figure has sides. The sum of the ' exterior ' angles diminished by four right angles is equal to twice as many right angles as the figure has sides. The sum of the ' differences of latitude ' being ' northings,' is equal to the sum of those which are... ## Introduction to Geometry: A Manual of Exercises for Beginners

William Schoch - Geometry - 1904 - 152 pages
...of a polygon without measuring them ? Exercise 33. If the sum of the interior angles of a polygon is equal to twice as many right angles as the figure has sides less four right angles, determine the sum of the interior angles of : 1. A six-sided polygon, or hexagon.... ## A text-book of engineering drawing and design

Sidney Herbert Wells - Machine design - 1905 - 246 pages
...depends upon Corollary I. of Euclid i., 32, which says, that " the interior angles of any straight lined figure together with four right angles are equal to...twice as many right angles as the figure has sides." The most common of the regular polygons used in engineering designs are the pentagon (five-sided),... ## Text Book of Topographical and Geographical Surveying

Sir Charles Frederick Close, Sir Charles Frederick Arden-Close - Surveying - 1905 - 376 pages
...together with the line AB form an enclosed figure, and the sum of all the interior angles should be equal to twice as many right angles as the figure has sides, less four right angles. We thus have a check on the observed horizontal angles. It should be carefully... ## Catalogue ...

Yale University. Sheffield Scientific School - 1905 - 1074 pages
...altitude is 3 in. PLANE GEOMETRY SEPTEMBER, 1909 1. The sum of all the interior angles of any polygon is equal to twice as many right angles as the figure has sides, less four right angles. 2. The angle between two chords which intersect within a circle is measured... ## Annual Report - Dept. of Education

Saskatchewan. Department of Education - Education - 1906 - 188 pages
...the triangle are together equal to two right angles. — I. 32. (6) What is a Corollary ? Show that all the interior angles of any rectilineal figure,...twice as many right angles as the figure has sides. (c) Derive the magnitude of an angle of a regular octagon. (d) If the exterior vertical angle of an... 