# How is the circumference

often have to work with geometric figures, calculations that defy easy explanation.If required to find the area of ​​a square or rectangle, they may be divided into some parts and intuitively display the correct formula.However, the length of the circle - the object is not quite the standard for ordinary students.Often there is a lack of understanding of the topic.Let's see what it is.

The circle itself is formed by two parameters: the radius and the position of the geometric center.Last versed in high school, so it is of little interest to us.But first sets the basic properties, such as area.Circumference actually depends only on the radius and is calculated by the following formula:

L = 2np

For the desired figure L. accept factor P ("P") is a constant.In order to successfully meet the challenges in the school enough to know that P = 3.14.However, not always necessary to substitute this value, since it is very simplistic.If it is a large scale, it is necessary to take into account the considerable number of decimal places.Therefore, in many cases, it is a more acceptable answer in a general way without any rounding.Keep in mind that the calculation of the circumference depends on the radius.It is a measure of how far removed from all points of the circle center.Accordingly, the greater this parameter, the longer arc.Like conventional distance metrics, L is measured in meters.R - radius.

In a real world there are complicated tasks.For example, when the required length of the arc of a circle.Here the formula a bit more complicated.It should be understood that it is based on the basic laws, but you cut off unnecessary part of the length.In general terms, it can be written as:

L = 2np / 360 * n

As you can see, there was one new variable n.This is a clear indication.The entire circumference was divided into 360 degrees.Thus, it became known how many meters falls by 1 degree.Further, by substituting the value of the desired turn around the axis instead of the letter n, we get a long-awaited answer.Taking the unit segment, we are in proportion to its increased n times.

Why in real life you have to know what is the circumference?This question is impossible to give an answer that would cover all areas of application.But to begin with primitive reference clock.Knowing the range of motion of the second hand, you can find the distance that it has to go in a minute.After become known path and time, we can find the speed with which it moves.And then will only deepen people engaged for hours.If the cyclist is moving on a circular track, its travel time is dependent on the speed and radius.You can find and acceleration.The washing machine is also not without indicator that we are almost dismantled.There's circumference is needed for calculating the speed (after all rests on the distance) is done for a certain amount of time.In broader terms because of the length of the circumference predicted movement of the planets in their orbits, and so on.

Thus, for a clear understanding of the subject to remember just two formulas.This knowledge will be useful to you not only in school for good grades, but also in real life.