Kamis, 05 Maret 2009

cube

Cube

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Regular Hexahedron
Cube
(Click here for rotating model)
Type Platonic solid
Elements F = 6, E = 12
V = 8 (χ = 2)
Faces by sides 6{4}
Schläfli symbol {4,3}
Wythoff symbol 3 | 2 4
2 4 | 2
2 2 2 |
Coxeter-Dynkin Image:CDW_ring.pngImage:CDW_4.pngImage:CDW_dot.pngImage:CDW_3.pngImage:CDW_dot.png
Image:CDW_ring.pngImage:CDW_4.pngImage:CDW_dot.pngImage:CDW_2.pngImage:CDW_ring.png
Image:CDW_ring.pngImage:CDW_2.pngImage:CDW_ring.pngImage:CDW_2.pngImage:CDW_ring.png
Symmetry Oh
or (*432)
References U06, C18, W3
Properties Regular convex zonohedron
Dihedral angle 90°
Cube
4.4.4
(Vertex figure)

Octahedron
(dual polyhedron)
Cube
Net

A cube[1] is a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex. The cube can also be called a regular hexahedron and is one of the five Platonic solids. It is a special kind of square prism, of rectangular parallelepiped and of 3-sided trapezohedron. The cube is dual to the octahedron. It has cubical symmetry (also called octahedral symmetry). A cube is the three-dimensional case of the more general concept of a hypercube, which exists in any dimension.


Formulae

For a cube of edge length a,

surface area 6a2
volume a3
radius of circumscribed sphere \frac{{\sqrt 3} a}{2}
radius of sphere tangent to edges \frac{a}{\sqrt 2}
radius of inscribed sphere \frac{a}{2}

As the volume of a cube is the third power of its sides a×a×a, third powers are called cubes, by analogy with squares and second powers.

A cube has the largest volume among cuboids (rectangular boxes) with a given surface area. Also, a cube has the largest volume among cuboids with the same total linear size (length + width + height).



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