# More About Circles And The Calculation Of Arc

Circles are special objects that have points at the same distance from the center. You must be aware of the term ‘radius’. It is the line that you get from that point towards the edge. When you do it’s double you will get the diameter of the circle. Every circle has a fixed equation that you can plot on the graph. Using that you can measure the value of its arc length as well. All the properties that you use in the circle will help you in various subjects.

## Different Properties

There are several properties that you can get in a circle. For example, the diameter has the potential to form two halves in it. This means that it reduces the area by half. There is a special value called pi that you will need to find the area. When you multiply this value (3.14) with the square of the radius, you get the value of the area. To find the congruency of the circles, the measurement of the radius is important. It is the only factor that you need to check and validate their congruency.

## Different Parts Of Circle

The radius is the most important part that sticks to a circle. Apart from this, you get a special element called chord as well. Draw any random line inside a circle and cut two edges. Make sure that it does not enter the center by any chance. This will help you to see what a chord is in reality. The interesting thing is that if you double the size, you get a diameter instantly. It is the chord that has the largest value.

Now if you just extend this chord, you get a special line as well. This is called a secant. All these lines are used in geometry to find various angles. You need to learn the properties to know the connection between them. Apart from these, you will get another line that touches the exterior part of a circle just once. It does not enter the circle, just passes outside touching gently. Mathematicians refer to this as a tangent and it is very important. When you extend the perpendicular to the center, it will automatically form 90 degrees. You can calculate the equation of a tangent if you know the properties of the circle. 