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. The papers set at the professional preliminary examination - Page 10
by College of preceptors - 1882 ## Euclid in Paragraphs: The Elements of Euclid: Containing the First Six Books ...

Euclid - Geometry - 1845 - 199 pages
...angles CBA, BAC, ACB, are equal to two right angles. Wherefore, if a side of a triangle, &c. QED COB. 1. All the interior angles of any rectilineal figure,...twice as many right angles as the figure has sides. the angles of these triangles are equal to twice as many right angles as there are triangles, that... ## Elements of plane (solid) geometry (Higher geometry) and trigonometry (and ...

Nathan Scholfield - 1845
...two right angles, taken as many times, less two, as the polygon has sides (Prop. XXVIII.) ; that is, equal to twice as many right angles as the figure has sides, wanting four right angles. Hence, the interior angles plus four right angles, is equal to twice as... ## The Elements of Euclid, the parts read in the University of Cambridge [book ...

Euclides - 1846
...angles BAC, ACB, CBA, are equal to two right angles. Wherefore, If a side of a triangle %c. QEU COR. 1. All the interior angles of any rectilineal figure,...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... ## Euclid's Elements: Or, Second Lessons in Geometry,in the Order of Simson's ...

Dennis M'Curdy - Geometry - 1846 - 138 pages
...ax. 2 ! (4) p. 27; (c) p. 13. (e)p.29; Cor. 1. All the interior angles of any rectilineal figure and four right angles, are equal to twice as many right angles as the figure has sides. For, about a point within the figure, as many triangles may be formed as the figure has sides, each... ## Euclid's Elements of geometry, the first three books (the fourth, fifth, and ...

Euclides - 1846
...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... ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

John Playfair - Euclid's Elements - 1846 - 317 pages
...as the figure has sides ; but the exterior are equal to four right angles ; therefore the interior are equal to twice as many right angles as the figure has sides, wanting four. PROP. II. Two straight lines, which make with a third line the interior angles on the... ## The English Journal of Education, Volume 1

Education - 1847
...liquidation of it. In how many years will the debt be paid off? OEOMETBY AND TRIGOSO1IETBY. SECTION I. — 1. All the interior angles of any rectilineal figure,...twice as many right angles as the figure has sides. 2. Equal triangles, upon equal bases in the same straight line, and towards the same parts, are between... ## Minutes of the Committee of Council on Education, Volume 1

...liquidation of it. In how many years will the debt be paid off? GEOMETRY AND TRIGONOMETRY. SECTION I. 1. All the interior angles of any rectilineal figure,...equal to twice as many right angles as the figure hag sides. 2. Equal triangles, upon equal bases in the same straight line, and towards the same parts,... ## A Complete Treatise on Practical Land-surveying: In All Its Departments ...

Anthony Nesbit - Plane trigonometry - 1847 - 426 pages
...accuracy of the previous work. Moreover, since the sum of all the interior angles of any polygon is equal to twice as many right angles as the figure has sides, lessened by four ; as the given figure has five sides, the sum of all its interior angles must be 2x5... 