The circle, circle are geometrical figures. In an extreme antiquity the men of science paid attention to certain regularities in the ratio of circle elements. In particular on relative interrelation of length of a circle and its diameter.
Instruction
1. Fir-trees to divide metric value of length of a circle into its diameter, always in private you receive the same number: 3.14. However, fraction this infinite, but always, for any sizes of circles, same. This universal number received name letters of the Greek alphabet "p.
2. Now in any practical case when you need to learn diameter of some circle, for example: covers on a tank, the hatch, a zontovy roof, a ditch, a roundish ravine and so on, you can, having measured circle length, to quickly calculate its diameter. For this purpose it is only necessary to apply a circle.L length formula = p DZdes: L – circle length, p – Pi's number equal 3.14, D – diameter of a circle. Rearrange in a circle length formula required in the left part and receive: D = L/p
3. Let's sort a practical task. Let's assume, you need to make a cover on a round country well, access to which is not present at present. Not a season, and improper weather conditions. But you have its circles given on length. Let's assume, these are 600 cm. In the specified formula we substitute values: D = 600/3.14 = 191.08 see. So, 191 cm make diameter of your well. Increase diameter to 2 meters taking into account an allowance for edges. Establish compasses on the radius of 1 m (100 cm) and draw a circle.