2. Circumference The distance around a circle

3. or

4. Find the circumference to the nearest tenth. 1. 2.

5. Circumference Writing your answer in terms of π EX: What is the exact measure of the circumference?

6. ON YOUR OWN: What is the exact measure of the circumference?

7. 3. The circumference of a half dollar is about 96 millimeters. Find the diameter of the coin to the nearest tenth. d ≈ 30.6 mm

8. 4. A circular flower garden has a circumference of 20 feet. Find the radius of the garden to the nearest hundredth. r ≈ 3.18 ft

9. GUIDED PRACTICE Simplify (Round to the nearest tenth): 1. 2. 3. 26.9 6.3 23.6

10. Arc Length a fraction of the circumference of a circle piece portion part section

11. Arc Length Corollary the ratio of the length of an arc to the circumference is equal to the ratio of the measure of the arc to 360º **

12. Example 1 Find the length of arc AB to the nearest hundredth. A  23.55 ft 90º 15 ft B A

13. Example 2 Find the length of arc AB to the nearest hundredth. A  4.19 m 40º 6 m B A

14. Example 3 Find the measure of arc AB to the nearest degree. mAB = 120º 18.84 m 9 m B A

15. Example 4 Find the radius of circle N to the nearest foot. r ≈ 2 ft 1.57 ft 45º B A N

16. Example 5 Find the circumference of circle Q. C ≈ 75.37 cm 41.87 cm 200º B A Q