Cube - the widespread geometrical figure familiar practically to everyone who is at least a little familiar with geometry. At the same time it has strictly certain quantity of sides, tops and edges.
The cube is the geometrical figure having 8 tops. In addition, the cube is characterized by a set of geometrical parameters which make him the special representative of family of polyhedrons.
Cube as polyhedron
In terms of geometry the cube belongs to the class of polyhedrons, representing a special case of the correct geometrical figure. In turn, within this science such of them which consist of identical polygons are recognized as regular polyhedrons, each of which has regular shape: it means that all its parties and corners are equal among themselves.
In a case with a cube each side of this figure really is a regular polygon as it represents a square. It, certainly, meets a condition about equality of all its corners and the parties among themselves. At the same time each cube consists of 6 sides, that is 6 correct squares.
Each side of a cube, that is each square which is its part it is limited to four parties equal among themselves which carry the name of edges. At the same time sides adjacent among themselves have adjacent edges therefore total number of edges of a cube not to equally simple work of quantity of sides on the number of the edges surrounding them. In particular, each cube has 12 edges. It is accepted to call the place of a convergence of three edges of a cube top. At the same time any edges which are crossed among themselves meet at an angle 90 °, that is are perpendicular each other. Each cube has 8 tops.
Properties of a cube
As all sides of a cube are equal among themselves, it gives ample opportunities on use of these data for calculation of various parameters of this polygon. At the same time the majority of formulas is based on the simplest geometrical characteristics of a cube, including those which are listed above. So, for example, let length of one side of a cube is taken for the size equal to a. In this case it is possible to understand without effort that the area of each side can be found by means of finding of the work of its parties: thus, the area of a side of a cube will be a^2. At the same time the total area of a surface of this polygon will be equal 6a^2 as each cube has 6 sides. Proceeding from these data it is also possible to find the volume of a cube which, according to a geometrical formula, will substantially represent the work of three of its parties - heights, lengths and width. And as lengths of all these parties on a statement of the problem are identical, therefore, for finding of volume of a cube to cube enough length of its party: thus, the volume of a cube will be a^3.