1. 7.2 Radian Measure

2. Radian Units of measure for angles: revolution, degree, & radian
Radian: a central angle has measure 1 radian if it intercepts an arc with length equal to the radius of the circle r r
 = 1 radian  r

3. Converting  radians = 180 1 revolution = 360 = 2 radians
(Circumf. of Circle = 2r)
 radians = 180
radians → degrees, multiply by
degrees→ radians, multiply by

4. Examples
Leave radian measure in terms of 
May omit word “radians”

5. Example 3 Change to decimal degrees Change to radians
(round to 4 dec. places)
Change to decimal degrees
Change to radians

6. Pg. 390 Chart
90
60
120
135
45
30
150
180 0
360
330
210
225
315
240
300
270

7. #703 Pg. 393 1 – 31 odd & Memorize chart on Pg. 390
Homework
#703 Pg – 31 odd & Memorize chart on Pg. 390