2. Circles & Circumference Standard Math

4. The circumference is the distance around a circle. Circumference Circumference is the perimeter of circles. Radius is half of the diameter. BACK

6. Find the Circumference of the circle. BACK

7. Find the circumference using the diameter. BACK

8. Find the circumference of the circle. You try this one. BACK

9. How would you find the diameter of a circle if you were only given the circumference? Find the diameter of a circle that has a circumference of 66. BACK

10. The circumference is the distance around a circle. diameter 1230.1 What is the connection between the diameter and the circumference? circumference The symbol, , is said as pie, and is about 3.14 The connection between the circumference and the diameter is

11. Find the diameter of the circle below: How to find the diameter given the circumference If you have the circumference: divide the circumference by 3.14 (  ). State the formula Substitute the values for  and C.

12. Find the circumference of the circle below: How to find the radius given the circumference If you have the circumference: divide this by, , 3.14 first to get the diameter. State the formula Substitute the values for  and C. Then divide the diameter by 2.

13. Calculate the missing numbers in the table below using the circumference formula below. What’s the formula? 17.584 14.13 5 C (cm)d (cm)r (cm) Use 3.14 as an approximation for . 10 4.5 5.6 2.8 2.25 31.4

14. Plenary You should now be able to find the radius or diameter of a circle given the circumference. You should know and use the formula for the circumference of a circle. or Find the diameter of the circle below.

16. Circles & Circumference Standard Math BACK