2. The Circle By Mr. Deepak Kumar

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

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

5. . 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

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

7. . O DI AMETER 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. A B DIAMETER = AB

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

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

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

11. Eg. If diameter of the circle is 10 cm then find its radius? . O Diameter = 10cm Sol. Radius =diameter / 2 radius=10 cm/ 2 radius =5 cm A B

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

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

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

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