1. The Circle
By Ranjana

2. O A
CIRCLE
Eg. ball,bangle,lemon.coin

3. CENTRE O A B
RADIUS
CENTRE : O
RADIUS : OA

4. . O
In a plane,each point of the circle is at equal distance from a fixed point.The fixed point is called the centre of the circle.
CENTRE = O

5. Radius O A
The distance from centre to any point on the circle is called radius of the circle.
RADIUS = OA

6. A
DI AMETER . O B
A Line segment passing through the centre of the circle and whose end points lie on the circle is called the diameter of the circle.
DIAMETER = AB

7. CIRCUMFERENCE . O
The length of the circle or the distance around it is called circumference of the circle.

8. . O A B
A Line segment whose both the ends touches the circumference and passes through the centre is called diameter.
DIAMETER : AB

9. Relation between radius and diameter
RADIUS = DIAMETER 2 . O A B
OB = AB 2

10. Eg. If diameter of the circle is 10 cm then find its radius?
Sol. Radius =diameter / radius=10 cm/ radius =5 cm . O A B
Diameter = 10cm

11. Eg. If radius of the circle is 6 cm,then find the diameter of the circle?
Sol. Diameter = 2 x Radius
Diameter = 2 x 6cm
Diameter = 12 cm .
Radius = 6cm A O

12. RELATION BETWEEN CIRCUMFERENCE AND DIAMETER
CIRCUMFERENCE = 3 x DIAMETER(APPROX)
CIRCUMFERENCE . O B A
DIAMETER

13. Eg. Find the circumference (approx) of the circle whose diameter is 10cm.
Sol. Circumference = 3 x diameter(approx)
Circumference = 3 x 10 cm
Circumference = 30 cm
CIRCUMFERENCE . O B A
DIAMETER=10 CM

14. EVALUATION
1. what is the relation between radius and diameter of the circle?
Sol .Radius=diameter/2
2. What is the relation between circumference and diameter of the circle?
Sol. Circumference=3Xdiameter(approx) .
3. In this figure O
radius
OA or OB is ______. A B
diameter
AB is ________.
centre
O is _________.

15. This powerpoint was kindly donated to www.worldofteaching.com
is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.