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The cube is so symmetrical figure that in order to find his side (rib) enough to know at least one of the main parameters of the cube. These include its volume, area of facets, length of the diagonal faces and the length of the diagonal of the cube (so-called "big diagonal").To find side of a cube if you know the area of one side, remove from the numeric value of the square faces of the square root. As a formula, this relationship can be written in the following form:S = √P where: – length of sides (faces) of the cube,
P - square faces of the cube.This formula is derived from the fact that the face of the cube is a square with a side equal to the edge of the cubeand square equal to the square of the ribs.
Finding the sides (edges) of a cube , given the volume similarly. As the volume of a cube is equal to the third order (cube) of the lengths of its edges, to determine the length of the edges of the cube remove from its scope the cube root. That is, use the formula:S = 3√V, where the volume of the cube.
(3√ - the function of extracting the cube root).
To find the sides (edges) of the cube diagonal of its faces, extract the square root of the square of the diagonal divided by two. As a formula this rule as follows:S = √(D2/2), where d is the length of the diagonal faces of the cube. The validity of this formula follows from the Pythagorean theorem because the diagonal and two adjacent edges form an equilateral right triangle, where the diagonal is the hypotenuse, and the edges of the legs.
To find the side (edge) of the cube on its diagonal (which is the diagonal of the cubeand not the faces) and extract the square root of one third of the square of the length of this diagonal. That is, use the same previous formula:S = √(L^2/3).This formula is also derived based on the Pythagorean theorem because the diagonal of the cube, the diagonal edge and the edge of the cube form a rectangular (but longer shaft than crossbar) triangle.