 | William Pease - 1856 - 108 pages
...or Duodecagon, twelve sides. Others are named, as polygons of thirteen or fourteen sides, etc. 64. A Regular polygon has all its sides, and all its angles equal ; if this is not the case, the polygon is Irregular. 65. The angle at the Circumference of a polygon is... | |
 | Lucius D. Gould - 1857 - 464 pages
...eight ; a nonagon, nine ; a decagon, ten ; an undecagon, eleven; and a dodecagon, twelve sides. 38. A regular polygon has all its sides and all its angles...they are not both equal, the polygon is irregular. ¿ 39. An equilateral triangle is, also, a regular figure of three sides, and the square is of four,... | |
 | William Grier - Mechanical engineering - 1861 - 316 pages
...Octagon, eight ;^a Nonagon, nine ; a Decagon, ten ; an Undecagon, eleven ; and a Dodecagon, twelve sides. 42. A Regular Polygon has all its sides and all its...are not both equal, the polygon is irregular. 43. An Eauilateral Triangle is also a regular figure of three sides, and the Square is one of four : the former... | |
 | William Schofield Binns - 1861 - 238 pages
...angles are not right angles. (23) Kectilineal figures of more than four sides are called polygons. A regular polygon has all its sides and all its angles equal, otherwise it is termed irregular. A polygon takes its name from the number of sides of .which it is... | |
 | Great Britain. Committee on Education - Education - 1864 - 332 pages
...Octagon, eight ; a Nonagon, nine ; a Decagon, ten ; an Undecagon, eleven ; and a Dodecagon, twelve sides. A Regular Polygon has all its sides and all its angles equal. — If they are not equal, the polygon is Irregulai. Any figure is equilateral, when all its sides are equal : and it is... | |
 | Gerardus Beekman Docharty - Geometry - 1867 - 474 pages
...eight ; aNonagon, nine ; a Decagon, ten ; an .Undecagon, eleven ; and a Dodecagon, twelve sides. ^ 42. A Regular Polygon has all its sides and all its...Triangle is also a Regular Figure of three sides, and«the Square is one of four : the former being also called a Trigon, and the latter a Tetragon.... | |
 | Horatio Nelson Robinson - Arithmetic - 1875 - 496 pages
...its sides. 716. The Area of a plane figure is the surface included withiii the lines which bound it A regular polygon has all its sides and all its angles equal. A polygon of three sides is called a trigon, or triangle ; of four sides, a tetragmt, or quadrilateral... | |
 | Daniel W. Fish - Arithmetic - 1876 - 302 pages
...sides. 869. The Area of a plane figure is the surface included within the lines which bound it. (46O.) A regular polygon has all its sides and all its angles equal. The altitude of a polygon is the perpendicular distance between its base and a side or angle opposite.... | |
 | Horatio Nelson Robinson - 1875 - 472 pages
...its sides. 716. The Area of a plane figure is the surface included within the lines which bound it A regular polygon has all its sides and all its angles equal. A polygon of three sides is called a trigon, or triangle ; of four sides, a tetragon, or quadrilateral... | |
 | James Bates Thomson - Arithmetic - 1882 - 450 pages
...three or more straight lines. 798. The Perimeter of a polygon is the line by which it is bounded. 799. A Regular Polygon has all its sides and all its angles equal. 800. A polygon having three sides is called a triangle; four sides, a quadrilateral; five sides, a... | |
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A Pentagon is a polygon of five sides ; a Hexagon, of six sides ; a Heptagon, seven; an Octagon, eight; a Nonagon, nine ; a Decagon, ten ; an Undecagon, eleven ; and 4 Dodecagon, twelve sides. 
