1. Circular measure Area of a Circle Definition of radians Click on a topic Area of a Sector Exit Definition of 

2. Definition of  Exit back Page 1 Page 1 (Pi) next

3. Exit back Page 1 Page 1 next Take any size of circle.

4. d C Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

5. d C Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

6. d C Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

7. C d Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

8. C d Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

9. C d Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.

10. C d is about 3 times Exit back Page 1 Page 1 next C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle. dC

11. C d Exit back Page 1 Page 1 next This is true for any size of circle C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle. dC = 3.1415927 x

12. C d Exit back Page 1 Page 1 next This number is called  (pi) This is true for any size of circle C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle.  dC = x dC = 3.1415927 x

13. C d  dC = x  =3.1415927 dC = 3.1415927 x This number is called  (pi) This is true for any size of circle C is the Circumference, the distance around the outside. d is the Diameter. Take any size of circle. Exit back Page 1 Page 1 next

14. Definition Exit  S  S r radians r 1c1c1c1c Definition 2c2c2c2c Page 1 Page 1 3c3c3c3c 4c4c4c4c 5c5c5c5c 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

15. Definition Exit  = 1 radian 1c1c1c1c Definition S = r  S r radians r 2c2c2c2c Page 1 Page 1 3c3c3c3c 4c4c4c4c 5c5c5c5c 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

16. Definition Exit  = 2 radians 1c1c1c1c 2c2c2c2c Definition S = 2r  S r radians r Page 1 Page 1 3c3c3c3c 4c4c4c4c 5c5c5c5c 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

17. Definition Exit  = 3 radians 1c1c1c1c 2c2c2c2c 3c3c3c3c Definition S = 3r  S r radians r Page 1 Page 1 4c4c4c4c 5c5c5c5c 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

18. Definition Exit  = 4 radians 1c1c1c1c 2c2c2c2c 3c3c3c3c 4c4c4c4c Definition S = 4r  S r radians r Page 1 Page 1 5c5c5c5c 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

19. Definition Exit  = 5 radians 1c1c1c1c 2c2c2c2c 3c3c3c3c 4c4c4c4c 5c5c5c5c Definition S = 5r  S r radians r Page 1 Page 1 6c6c6c6c revolution 1 revolution c means circular measure i.e. radians

20. Definition Exit  = 6 radians 1c1c1c1c 2c2c2c2c 3c3c3c3c 4c4c4c4c 5c5c5c5c 6c6c6c6c Definition S = 6r  S r radians r Page 1 Page 1 revolution 1 revolution c means circular measure i.e. radians

21. Definition Exit  = 2  radians 1c1c1c1c 2c2c2c2c 3c3c3c3c 4c4c4c4c 5c5c5c5c 6c6c6c6c 1 revolution 1 revolution Definition S = 2  r  S r radians r Page 1 Page 1 c means circular measure i.e. radians

22. Area of a circle Exit back Page 1 Page 1 Show dimensions Show dimensions

23. Area of a circle Cut into sectors Cut into sectors r Exit back C =2  r Page 1 Page 1

24. Area of a circle Exit back C =2  r r Page 1 Page 1 Open out Open out

25. C2C2 r =  r Area of a circle C =2  r C2C2 =  r Exit back Page 1 Page 1 Push together Push together

26. Area of a circle C =2  r Exit back Page 1 Page 1 Area of rectangle Area of rectangle r  r

27. r Area =  r 2 Area of a circle C =2  r Exit back Page 1 Page 1

28. Area of a sector Exit back Page 1 Page 1 Show dimensions Show dimensions

29. Cut into small sectors Cut into small sectors Exit back Page 1 Page 1 Area of a sector S = r  r 

30. Exit back Page 1 Page 1 Open out Open out Area of a sector S = r  r

31. Exit back Page 1 Page 1 Open out Open out Area of a sector r2r2 r2r2 r

32. r Exit back Page 1 Page 1 Push together Push together Area of a sector r2r2 r2r2

33. r Exit back Page 1 Page 1 Area of a sector r2r2 Area of rectangle Area of rectangle

34. Area = ½ r 2  Exit back Page 1 Page 1 Area of a sector r r2r2