parts of a circle

By the term circle, we mean that the circular closed curve which is formed by joining the points which are plotted with the  compass around the fixed point and at the equal distance around it. This fixed distance is called the radius of the circle.  

There are different parts of a circle, some of them are as follows :

The point in between the circle is called the center of the circle. It is normally represented  by the alphabet O.

The boundary of the circle is called the circumference of the circle. It is also termed as the perimeter of the circle.

The distance from the center of the circle to the boundary of the circle is called the radius of the circle. 

If we draw any line segment in the interior of the circle, such that the end point of the line segment touches the boundary of the circle at both the ends, then we say that it is the chord of the circle.

There can be any number of chords which can be drawn inside the circle.  The chord of the circle which  passes from the center of the circle is the longest chord of the circle. We also call it as the diameter of the circle.  When a diameter is drawn inside the circle, we observe that the  diameter of the circle is equal to the two times of the radius of the circle. Thus it can be written as follows :

 Diameter = 2 * Radius

Or Radius of the circle = diameter / 2

 The line which we draw outside the circle and it touches only at one point  on the circle is called the tangent to the circle.  Also we must remember that the tangent to the circle is always perpendicular to the  radius of the circle at that particular point.

To learn about the Sampling Methods, we can take the help of maths online tutorials. We also come across the questions based on the sampling methods in the  icse board papers and In the next session we will discuss about area of circle.