1. Circumference Review

2. Review What is the relationship between a radius and a diameter? What does a circumference measure? What formulas do we use to calculate circumference? What do we use to represent pi?

3. Pi Equals? π = circumference/diameter ≈ π ≈ 22/7 or 3 and 1/7 We will use 3.14 3.141592653 589793238462643383279502884 1971693993751058209749445923078164062862089986 2803482534211706798214808651328230664709384460 9550582231725359408128481117450284102701938521 1055596446229489549303819644288109756659334461 2847564823378678316527120190914564856692346034 8610454326648213393607260249141273………. (on and on and on)

4. Find the Circumference of the circle. BACK

5. Find the circumference using the diameter. BACK

6. Calculate the following Using 3.14 for pi. –r = 6 –r = 13 Using 22/7 for pi. –r = 8 –d = 24

7. Circumference 2 Assignment Use 3.14 for pi 1)r = 4 2)r = 7 3)r = 9 4)d = 15 5)d = 22 6)d = 30 Use 22/7 for pi 1)r = 4 2)r = 7 3)r = 9 4)d = 15 5)d = 22 6)d = 30

8. Area of a Circle

9. Area The number of square units the figure covers

10. Area of a Circle

11. Find the Area of the circle.

13. Practice Problems Using 3.14 for pi –r = 6 –d = 14 Using 22/7 for pi –r = 8 –d = 24

14. Area of a Circle1 Assignment Use 3.14 for pi 1)r = 4 2)r = 9 3)d = 16 4)d = 22 Use 22/7 for pi 1)r = 4 2)r = 9 3)d = 16 4)d = 22

15. Area of a Circle