 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.  Plane Geometry - Page 87by Jacob William Albert Young, Lambert Lincoln Jackson - 1916 - 312 pagesFull view - About this book
 | 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 is n times two right... | |
 | Charles Davies - Geometry - 1872 - 464 pages
...similar. > For, the corresponding angles in each are equal, because any angle in either polygon is equal F to twice as many right angles as the polygon has sides, less four right angles, divided by the number of angles (B. L, P. XXVI., C. 4); and further, the corresponding sides are proportional,... | |
 | Walter Smith - Geometrical drawing - 1872 - 72 pages
...the number of degrees in the angle of a regular polygon. The rule is, that the sum of the internal angles of a polygon is equal to twice as many right angles as the figure has sides, minus four angles. The reason of this is, that a regular polygon has the same number... | |
 | William Chauvenet - Mathematics - 1872 - 382 pages
...is twice as many right angles as the polygon has sides. But the sum of the interior angles alone is twice as many right angles as the polygon has sides, less four right angles (100) ; therefore the sum of the exterior angles is equal to four right angles. This is also proved... | |
 | William Frothingham Bradbury - Geometry - 1872 - 124 pages
...therefore 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... | |
 | William Frothingham Bradbury - Geometry - 1872 - 262 pages
...equal, GC = D II ; therefore, if we add the two equations, we shall have 2 EF= AD + BC or 67. The Bum of the interior angles of a polygon is equal to twice as many riff/d angles as it has sides minus two. Let ABC D EF be the given polygon ; the sum of all the interior... | |
 | New York Board of Education, New York (N.Y.). Board of Education - History - 1873 - 166 pages
...respectively equal. 6. The sum of the three angles of a triangle is equal to two right angles. I7. 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. 8. The sum of the exterior angles of a polygon is equal to... | |
 | William Frothingham Bradbury - Geometry - 1873 - 132 pages
...DFH are equal, GO = DH ; therefore, if we add the two equations, we shall have THEOREM XX. 67, The sum of the interior angles of a polygon is equal to twice as many right angles as it has sides minus two. Let ABGDEF be the given polygon ; the sum of all the interior angles A, B,... | |
 | William Frothingham Bradbury - Geometry - 1873 - 288 pages
...equal, G С = DH ; therefore, if we add the two equations, we shall have THEOREM XX. 67« The surn of the interior angles of a polygon is equal to twice as many right angles as it has sides minus two. Let А B С DEF be the given polygon ; the sum of all the interior angles A,... | |
 | Henry Angel - Geometry - 1873 - 192 pages
...43. All the angles of a regular polygon are equal, and if they be added together their sum will equal twice as many right angles as the polygon has sides, less four. (Euclid, Bk. I., Def. 32.) For definitions, <fcc., of Polygons, see Chapter II. Thus, in an octagon,... | |
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