1. Holt Geometry 3-1 Lines and Angles  Paper for notes  Pearson 13.3

2. Holt Geometry 3-1 Lines and Angles TOPIC: 13.3 Radian Measure Name: Daisy Basset Date : Period: Notes Objective: Understand radian measure of an angle as the length of the arc on the unit circle included by the angle.

3. Holt Geometry 3-1 Lines and Angles Key Concept  Proportion Relating Radians & Degrees  Converting Between Radians & Degrees  Length of an Intercepted Arc

4. Holt Geometry 3-1 Lines and Angles Vocabulary  Central Angle  Intercepted Arc  Radian

5. Holt Geometry 3-1 Lines and Angles  Notes 13.3 13.3 Handout  Calculator

6. Holt Geometry 3-1 Lines and Angles 1. Find the measure in degrees or in radians.

7. Holt Geometry 3-1 Lines and Angles A. What is the degree of measure of an angle of radians?

8. Holt Geometry 3-1 Lines and Angles Multiply by radians  degrees

9. Holt Geometry 3-1 Lines and Angles An angle of radians measures _____.

10. Holt Geometry 3-1 Lines and Angles B. What is the radian measure of an angle of 27º?

11. Holt Geometry 3-1 Lines and Angles Multiply by degrees  radians

12. Holt Geometry 3-1 Lines and Angles An angle of 27º measures __ radians.

13. Holt Geometry 3-1 Lines and Angles C. What is the degree of measure of an angle of radians?

14. Holt Geometry 3-1 Lines and Angles Multiply by radians  degrees

15. Holt Geometry 3-1 Lines and Angles An angle of radians measures ___.

16. Holt Geometry 3-1 Lines and Angles 2. Find the exact values and then round to the nearest 100 th.

17. Holt Geometry 3-1 Lines and Angles A. cos ( radians) sin ( radians)

18. Holt Geometry 3-1 Lines and Angles cos ( radians) = ≈ sin ( radians) = ≈

19. Holt Geometry 3-1 Lines and Angles B. cos ( radians) sin ( radians)

20. Holt Geometry 3-1 Lines and Angles cos ( radians) = ≈ sin ( radians) = ≈

21. Holt Geometry 3-1 Lines and Angles 3. Use the given circle and find the arc length. Round to the nearest 10 th.

22. Holt Geometry 3-1 Lines and Angles A. Find s. arc length =radius m central  s = 3

23. Holt Geometry 3-1 Lines and Angles s =

24. Holt Geometry 3-1 Lines and Angles Summary Explain how to convert degrees to radians and radians to degrees.

25. Holt Geometry 3-1 Lines and Angles Hmwk 13.3 A: Practice: 7 – 33 ODDS Work on the Study Plan

26. Holt Geometry 3-1 Lines and Angles Hmwk 13.3 A: Practice: 7 – 33 ODDS ONLY

27. Holt Geometry 3-1 Lines and Angles  Notes 13.3 13.3 Handout  Calculator

28. Holt Geometry 3-1 Lines and Angles B. Find b. arc length =radius m central  b =b = 3

29. Holt Geometry 3-1 Lines and Angles b =b = b =b =

30. Holt Geometry 3-1 Lines and Angles 4. The length of a windshield wiper arm is 20 in. and it rotates through an angle of 105º.

31. Holt Geometry 3-1 Lines and Angles What is the length of the arc to the nearest inch that the wiper arm travels as it moves across the windshield.

32. Holt Geometry 3-1 Lines and Angles 105º 20 in x

33. Holt Geometry 3-1 Lines and Angles arc length = radius m central  (in radians) degrees  radians Multiply by

34. Holt Geometry 3-1 Lines and Angles arc length = radius m central  (in radians) x =20 The wiper arm travels about _____ as it moves across the windshield. 37 in.

35. Holt Geometry 3-1 Lines and Angles Summary Explain how to find an arc length given a radius and measure of the central angle.

36. Holt Geometry 3-1 Lines and Angles Hmwk 13.3 B: Math XL Work on the Study Plan