# What is the scope of NET 2

## Circle calculation: area, radius, diameter, circumference - all formulas

This article is about the topic Circle calculation. Basically this is very simple, you just have to know a few formulas and it'll all work by itself. We're going to introduce you to a few equations so that you can see the relationships between Radius, area, diameter and understand scope better. The Circle calculation belongs to mathematics.

Now let's take a look at a few facts about the Circle calculation at.

### Examples and formulas in the Circle calculation

First there is that radius one Circle. The radius gives the straight distance from the center of the circle to the edge of the circle. According to that is the twice the radius, logically, the diameter of the circle.

### Diameter = 2 x radius

To illustrate this again in numbers. If the radius of a circle is 3 meters, then that is diameter 6 meters.

The number π (Pi) is also required. This is usually given in schools as 3.14159. Actually, however, this number has an infinite number of descendants, since after the largest there is always a larger one and below the smallest there is always something smaller, at least if you calculate the circumference of a circle.

### Radius, area and the diameter in the circle calculation

Let's start with calculating the area of ​​a circle. Here are the formulas:

### Area = Pi times the radius squared.

Area = Pi times the diameter squared divided by 4.

So stands A. for the surface, π for the district number 3.14159, r for the radius and d for the diameter. It is important that for area, radius and diameter the same unit of measurement is used in the formula.

### Example for the area calculation

We have a circle with that radius from 0.34 meters. With the formulas listed above, we will now use the surface To calculate. To do this, we just have to use the values ​​known to us. So here we calculate using the radius:

And here we calculate using the diameter:

So you see, it's very simple.

### Example of calculating the radius of a circle

We have a surface in the size of 1.2m ^ 2. What is the measure now radius?

To do this, we simply have to rearrange the formula and use the values ​​known to us, i.e. the surface and the number pi.

So simply rearrange A = π x r ^ 2 so that the value you are looking for is on its own. Anyone who has done this a few times has mastered it in their sleep.

### Example of calculating the circumference of a circle

Here we need a new formula, namely:

The value U stands for scope. The meaning of the other abbreviations has already been explained and should be known.

So here is an example of how to calculate the Circumference of a circle.

A circle has one radius of 5 meters, what is the circumference?

This can of course also be done via the diameter calculate.