1. Draw Angles DMS  decimal degrees Degrees  Radians 5.1 Angles and Their Measure

2. Terminal side Initial side Positive angle of rotation

3. Initial side Terminal side negative angle of rotation

4. Draw the angle… Reference Angle – measure from the nearest x-axis to the terminal ray (always positive)

5. Draw the angle… Reference Angle

6. Draw the angle… Reference Angle

7. Draw the angle… Reference Angle

8. Degrees, Minutes, Seconds A ‘degree’ is divided into 60 ‘minutes’. A ‘minute’ is divided into 60 ‘seconds’ This allows us to create angles with a much greater degree of accuracy (very important in navigation).

9. For convenience, we can write the angle measure in decimal form…

10. We can also write a decimal form of the angle measure in DMS (degrees, minutes, seconds) form…

11. Radians - preferred in mathematics A radian is another way to measure angles 1 radian is the size of an angle needed to create an arc that is the same length as the radius of a circle.

12. Radians

13. Convert Degrees  Radians 1 4

14. p.366 # 11-16, 23-25, 29-31, 35-46 Assignment