In a school course of geometry the pupils generally consider the areas of regular polygons. Meanwhile, for the solution of a set of practical tasks quite often it is necessary to deal with the wrong geometrical figures. Faces this problem of people also when determining the sizes of the seasonal dacha or house adjoining territory, and when calculating amount of fabric for sewing, and in many cases. It is possible to calculate the area of the wrong figure in several ways.
It is required to you
- - wrong geometrical figure;
- - measuring tools;
- - transparent plastic;
- - ruler;
- - square;
- - ball pen.
Instruction
1. Consider a geometrical figure and define what its parameters are known to you. It can be lengths of the parties or corners. Depending on the set parameters also choose a way of determination of the area. For example, divide it into several figures which formulas of calculation of the area you know. One of the most widespread methods — to carry out diagonals from one corner to all other tops. In this case you need to know a formula of calculation of the area of any triangle. But nobody forbids to divide the set figure and into other polygons. For example, when calculating the area of a floor in the room with a niche it is more convenient to divide the wrong figure into two rectangle or a square.
2. For determination of the area of not too big detail it is possible use a palette. It can be made most. Cut off a rectangular piece of any transparent plastic. Divide it into squares which area is known to you — for example, 1х1 or 0.5х0.5 cm. The ruler and the square have to be exact. Impose a palette on a detail. Count full small squares, then — incomplete. Divide quantity of incomplete squares into 2 and add on result to number of whole. The more small than division on a palette — the more precisely there will be a result. It is similarly possible to count also land area. The palette will be served by a grid from squares with the party of 1х1 m, nacherchenny on the earth or noted by pegs with the cords stretched between them. It is possible to be limited also to a marking of the territory on strips.
3. With large areas it is possible to arrive and differently. Take the most exact plan of the site or house adjoining territory. Determine scale. Use one of the offered ways. Then transfer the received number of square centimeters to the necessary scale.