Often you have to work with geometricfigures, calculations for which can not be easily explained. If you want to find the area of a square or a rectangle, you can conditionally divide them into parts and intuitively derive the correct formula. However, the length of the circle is not quite a standard object for ordinary schoolchildren. Often there is a misunderstanding of this topic. Let's see what's wrong.
The circle itself is formed due to two parameters:radius and geometric position of the center. The latter is versed in high school, so he is of little interest to us. But the first one sets the basic properties, for example, the area. The circumference of a circle depends, in fact, only on the radius and is calculated by the following formula:
L = 2PR
For the sought indicator we accept L.The factor n ("Pi") is a constant. To successfully solve problems in school it is enough to know that P = 3.14. However, it is not always necessary to substitute this value, since it is very simplistic. If it is a question of large scales, it is necessary to take into account a considerable amount of signs after the decimal point. Therefore, in many cases, the answer is generally more acceptable in general form without any rounding. Remember that calculating the length of a circle depends only on the radius. This is an indicator of how far removed all points of the circle from the center. Accordingly, the larger this parameter, the longer the arc. Like the usual distance measurements, L is measured in meters. P is the radius.
In more real conditions, there are complicatedtasks. For example, when the length of the arc of a circle is needed. Here the formula is a little more complicated. It should be understood that it is based on the basic regularity, but cuts off part of the length unnecessary to you. In general, it can be written as follows:
L = 2PR / 360 * n
Apparently, there is one new variable n.This is a visual indication. The entire circumference was divided by 360 degrees. Thus, it became known how many meters are at 1 degree. Further, substituting the values of the required turnover around the axis instead of the letter n, we get the long-awaited answer. Taking a unit interval, we proportionally increased it by a factor of n.
For what in real life do you need to know what is equal tocircumference? This question can not be answered, which would cover all fields of application. But for the introduction begin with primitive hours. Knowing the radius of the second hand, you can find the distance that it should pass in a minute. After the path and time become known, we can find the speed with which it moves. And then only people who are engaged in hours will go deeper. If the cyclist is moving along a circular track, then its travel time depends on speed and radius. You can find and accelerate it. In washing machines also does not do without an indicator, which we almost disassembled. There the length of the circle is necessary for counting the revolutions (all in fact rests against the distance), performed for a certain amount of time. In more scale conditions, due to the circumference of the circumference, the motion of the planets along the orbits is predicted, and so on.
Thus, for a clear understanding of the topic, you need to remember only two formulas. This knowledge will be useful to you not only in school for good grades, but also in real life.
