Square - a flat correct quadrangle or an equilateral rectangle. So correct that all its characteristics are among themselves equal: parties, diagonals, corners. Because of equality of the parties the formula for calculation of the area of a square changes a little that does not complicate a task at all.

## Instruction

1. The standard formula for calculation of the area of a rectangle consists in the work of its different parties and has an appearance: S=a*b where s is the area of a flat figure, an and b of its party, the having different lengths. To calculate the area **of a square**, it is necessary to substitute its parties in the above-stated formula. But they are equal, it turns out to find the area of the correct rectangle it is necessary to square its party. S = (a) in the second degree.

2. Now on a certain formula of the area of a square it is possible to find its party, knowing numerical value of the area. For this purpose it is necessary to solve the equation of the second degree: S=(a) in the second degree. There is a party "and" by extraction from under a root of value of the area of a figure: and = a root square of (S). Example: it is necessary to find the party of a square if its area is sixty four square centimeters. Decision: if 64= (a) in a kavdrata, ""and"" equally in a root from sixty four. It turns out eight. Answer: eight square centimeters.

3. If the solution of a square root is beyond tables of squares and the answer it is impossible whole, will save the microcalculator. Even on the simplest machine it is possible to find value from under a square root. For this purpose gather the following set of buttons: ""number"" which expresses a radicand and ""the sign of a root"". The answer on the screen will also be subradical value.