| William Frothingham Bradbury - Geometry - 1872 - 124 pages
...the sum of the angles of all the triangles, that is, the sum of the interior angles of the polygon, is equal to twice as many right angles as the polygon has sides minus two. PRACTICAL QUESTIONS. 1. Do two lines that do not meet form an angle with each other ? Two... | |
| Edward Olney - Geometry - 1872 - 472 pages
...re.entrant angle. FIG. 186. PROPOSITION XT. 253. Theorem. — The sum of the inferior angles of a polygon s* equal to twice as many right angles as the polygon has sides, less four right angles. DEM. — Let n be the number of sides of any polygon; then the sum of its angles... | |
| Adrien Marie Legendre - Geometry - 1874 - 500 pages
...similar. For, the corresponding angles in each are equal, because any angle in F( >C either polygon is equal to twice as many right angles as the polygon has sides, less four right angles, divided by the number of angles (B. I, P. XXVI , C. 4); and further, the corresponding... | |
| Edward Atkins - 1874 - 428 pages
...circle, the sum of the angles in the segments exterior to the polygon, together with two right angles, is equal to twice as many right angles as the polygon has sides. 20. Draw the common tangents to two given circles. 21. From a given point draw a straight line cutting... | |
| Edward Atkins - 1874 - 426 pages
...circle, the stun of the angles in the segments exterior to the polygon, together with two right angles, is equal to twice as many right angles as the polygon has aides. SO. Draw the common tangents to two given circles. 21. From a given point draw a straight line... | |
| William Alexander Willock - Circle - 1875 - 196 pages
...corresponding external is equal to two right angles, the sum of all the internal and all the external is equal to twice as many right angles as the polygon has angles, or sides. If we take from this latter sum the four right angles to which the external angles... | |
| William Guy Peck - Conic sections - 1876 - 412 pages
...angles of each triangle is two right angles ; hence, the sum of all the angles of all the triangles is equal to twice as many right angles as the polygon has sides. But, the sum of the angles of the polygon is equal to the sum of all the angles of all the triangles... | |
| Edward Olney - Geometry - 1877 - 272 pages
...one re-entrant angle. PROPOSITION XV. 233. TJieorem, — The sum of the interior angles of a polygon is equal to twice as many right angles as the polygon has sides, less four right angles. FIo. 187. DEM. — Let n be the, number of sides of any polygon; then the sum... | |
| William Frothingham Bradbury - Geometry - 1880 - 260 pages
...the sum of the angles of all the triangles, that is, the sum of the interior angles of the polygon, is equal to twice as many right angles as the polygon has sides minus two. \ DEFINITIONS. 126.. Every proposition has an hypothesis (19), and a conclusion. Thus in... | |
| Alfred Hix Welsh - Geometry - 1883 - 326 pages
...if, etc. QUERY. THEOREM XXVI. The sum of the interior angles of a polygon, plus four right angles, is equal to twice as many right angles as the polygon has sides. For, take any polygon, as ABCD E. If from any point within it, as F, lines be drawn to the vertices... | |
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