Section 3-4Radian Measures of

Angles

Definition:

Radian Measure of an Angle

r = 1r = x

1 unit

x units

1 radian

A 1 radian angle subtends the same fraction of a circle regardless of the length of the radius.

Procedure:

Radian-Degree ConversionTo find the radian measure of q, multiply the degree measure by

To find the degree measure of q, multiply the radian measure by

Radian Measures of Some Special Angles

http://www.lsquaredmath.us/radians/index.php

http://www.lsquaredmath.us/radians/targetPractice.php

Angle Target Practice

Radian Measure and the Unit Circle

1

A

B

C

D

E

F

G

Convert 2250 to radians

H

2 Convert 4.73 radians to degrees

3 Find the radian measure of an angle whose sine is 0.4

4 Find the degree measure of an angle whose sine is 0.4

5 Find the exact value of

A

B

C

D

E

F

G

H Undefined

Radian Mode: Degree Mode:

Your calculator:

Attachments