Circle, it is one of the basic shapes which we come across in our day to day life. The distance between the center of the circle and the edges remains the same from any given point on the edge. It is round in shape having a definite circumference. IN other words you can all a perfect pound as a circle.

Chord of the Circle:

It is any straight line which passes from two points of a circle.

Diameter of a circle (d):

The straight line which passes through the center and reaches the circumference on both the ends is called as diameter of a circle. The size of the diameter of a circle will be twice the size of the diameter. In simple terms, the diameter can be represented as

d= 2 r

where r is the radius

Radius of a circle (r):

The distance between the center of the circumference and the radius is called as radius.

Radius of a circle formula is r = C/2π, where C is circumference, π value is 3.14

Major Arc:

It refers to an arc of the circle whose pi radians is greater than or equal to 180 degrees.

Minor Arc:

It refers to an arc of the circle whose pi radians is less than or equal to 180 degrees.

Circumference of a circle:

This reference to the distance in a circle. The circumference of a circle is similar to the perimeter of a rectangle. The ratio between the circumference and the diameter remains constant 3.14 or π

NCERT solutions for class 9 maths chapter 10 circles pdf explains you the topic of radius, circumference, diameter, major and minor arc with examples