Introduction to Circles

A figure made by all the points which are at the same distance from a fixed point is called a Circle.

1. Center

The fixed point is known as the centre of the circle.

2. Radius

The distance from any point on the circle to the fixed point is the radius. Any line segment which joins the centre and any point on the circle is known as the Radius.

3. Chord

Any line segment made by joining any two points on the boundary of the circle is called Chord.

4. Diameter

Diameter is two times the radius. It is the longest chord on the circle which passes through the centre. All the diameters have the same length.

5. Circumference

The length of the boundary of the circle is called the circumference of the circle.

6. Arc

An arc is the part of the circle joining two points on the circumference of the circle.

7. Sector

An area made by an arc and two radii of the circle, by joining the centre to the endpoints of the arc is called Sector.

8. Segment

An area made by a chord and an arc of the circle is called Segment.