## Related Articles

- segÂ·ment. // American Heritage Student Science Dictionary;2009, p306
Several definitions of the term "segment" are presented. Segment is the portion of a line between any two of its points. It can also refer to the region bounded by an arc of a circle and the chord that connects the endpoints of the arc. Segment is also the portion of a sphere included between a...

- sphere. // American Heritage Student Science Dictionary;2009, p321
A definition of the term "sphere" is presented. It refers to a three-dimensional geometric surface having all of its points the same distance from a given point.

- sphere. // Taber's Cyclopedic Medical Dictionary;2005, p2041
The article presents a definition for the term "sphere," which refers to a ball or globelike structure.

- On extension of isometries between the unit spheres of normed space E and l p ( p > 1). Ji Jin Yi; Rui Dong Wang // Acta Mathematica Sinica;Jul2009, Vol. 25 Issue 7, p1139
In this paper, we study the extension of isometries between the unit spheres of normed space E and l p( p > 1). We arrive at a conclusion that any surjective isometry between the unit sphere of normed space l p( p > 1) and E can be extended to be a linear isometry on the whole space l p( p > 1)...

- cone. // American Heritage Student Science Dictionary;2009, p79
A description of cone is given. A cone is known as a three-dimensional surface or solid object in which the base is a circle and the sides narrow to form a point. The surface of a cone is formed mathematically by moving a line that passes through a fixed point (the vertex) along a circle.

- polyhedral. // Taber's Cyclopedic Medical Dictionary;2005, p1725
A definition of the term "polyhedral" is presented. It refers to the bodies who have many surfaces.

- Bulk and interior packing densities of random close packing of hard spheres. Yugong Wu; Zhigang Fan; Yuzhu Lu // Journal of Materials Science;May2003, Vol. 38 Issue 9, p2019
The packing densities of random close packing of equal hard spheres (RCPHS) are studied. The RCPHS is generated by a rearrangement algorithm with an optimization subroutine. Traditionally defined packing density, bulk density, is found to be 0.635 Â± 0.002 by extrapolation to infinite number...

- PoincarÃ©'s conjecture (1904) Mathematics. // Dictionary of Theories;2002, p419
A definition of the term "PoincarÃ©'s conjecture" is presented. It is a term used in mathematics advanced by Jules Henri PoincarÃ©. It holds that every simply connected three-dimensional compact manifold is topologically equivalent to a three-dimensional sphere.

- How Many SIDES and FACES Do They Have? // World Almanac for Kids;1997, p152
Provides diagrams of different shapes, both two-dimensional and three-dimensional. Diagram of a square, a cube, a sphere, a circle, etc.