Circles Class 9 PPT

 Page 1


 
 
 
 
 
 
CIRCLES 
 
  
 
 
 
 
 
 
 
 
 
 
 
Page 2


 
 
 
 
 
 
CIRCLES 
 
  
 
 
 
 
 
 
 
 
 
 
 
           CIRCLES 
Introduction 
We come across many objects in our daily 
life which are round in shape, such as 1 
rupee coin, wheels of vehicles , bangles 
etc. How can we define a circle? 
A circle is a closed figure in a plane and it 
is the collection of all the points in the 
plane which are at a constant distance 
from a fixed point in the plane. The fixed 
point is the centre of the circle and the 
constant distance is the radius of the 
circle. 
Page 3


 
 
 
 
 
 
CIRCLES 
 
  
 
 
 
 
 
 
 
 
 
 
 
           CIRCLES 
Introduction 
We come across many objects in our daily 
life which are round in shape, such as 1 
rupee coin, wheels of vehicles , bangles 
etc. How can we define a circle? 
A circle is a closed figure in a plane and it 
is the collection of all the points in the 
plane which are at a constant distance 
from a fixed point in the plane. The fixed 
point is the centre of the circle and the 
constant distance is the radius of the 
circle. 
 
 
 
Circles and its related 
terms 
Circumference of a circle is 
the length of the complete 
circular curve constituting 
the circle. 
 
Chord of a circle is a line 
segment joining any two 
points on the circle. 
 
PQ is a chord. 
 
 
 
  
Page 4


 
 
 
 
 
 
CIRCLES 
 
  
 
 
 
 
 
 
 
 
 
 
 
           CIRCLES 
Introduction 
We come across many objects in our daily 
life which are round in shape, such as 1 
rupee coin, wheels of vehicles , bangles 
etc. How can we define a circle? 
A circle is a closed figure in a plane and it 
is the collection of all the points in the 
plane which are at a constant distance 
from a fixed point in the plane. The fixed 
point is the centre of the circle and the 
constant distance is the radius of the 
circle. 
 
 
 
Circles and its related 
terms 
Circumference of a circle is 
the length of the complete 
circular curve constituting 
the circle. 
 
Chord of a circle is a line 
segment joining any two 
points on the circle. 
 
PQ is a chord. 
 
 
 
  
Arc of a circle is a part of the 
circle. 
Any two points A and B of a 
circle divide the circle into 
two parts. The smaller part is 
called the minor arc and the 
larger part is called the 
major arc of the circle. If the 
two parts are equal, AB is a 
diameter of the circle and 
each part is called a semi 
circle. 
Page 5


 
 
 
 
 
 
CIRCLES 
 
  
 
 
 
 
 
 
 
 
 
 
 
           CIRCLES 
Introduction 
We come across many objects in our daily 
life which are round in shape, such as 1 
rupee coin, wheels of vehicles , bangles 
etc. How can we define a circle? 
A circle is a closed figure in a plane and it 
is the collection of all the points in the 
plane which are at a constant distance 
from a fixed point in the plane. The fixed 
point is the centre of the circle and the 
constant distance is the radius of the 
circle. 
 
 
 
Circles and its related 
terms 
Circumference of a circle is 
the length of the complete 
circular curve constituting 
the circle. 
 
Chord of a circle is a line 
segment joining any two 
points on the circle. 
 
PQ is a chord. 
 
 
 
  
Arc of a circle is a part of the 
circle. 
Any two points A and B of a 
circle divide the circle into 
two parts. The smaller part is 
called the minor arc and the 
larger part is called the 
major arc of the circle. If the 
two parts are equal, AB is a 
diameter of the circle and 
each part is called a semi 
circle. 
Interior , Exterior and circular 
region. 
 
The plane region lying inside 
the circle is called the interior 
of the circle.  
The circle together with its 
interior is called  
circular region. 
 
The part of the plane region 
out side the circular region is 
called the exterior of the circle.