Radian Measure

Radian: The radian measure of an angle as the length of the arc on the unit circle subtended by the angle

Positive Angles

Angles measured counterclockwise are positive.

Radians measured counterclockwise are positive.

Negative Angles

Angles measured clockwise are negative.

Radians measured clockwise are negative.





Converting Degrees to Radians

To convert radians to degrees and vice versa:

  1. Know to which unit you are converting to
  2. Multiply by the proper conversion factor
  3. Simplify and reduce, if possible

Convert to Radians

Because we are converting degrees to radians, we have to multiply the degrees by pi/180.




Write the operation as one fraction.



Reduce the fraction to lowest term possible

Convert to degrees

Because we are converting radians to degrees, we have to multiply the degrees by 180/1pi.




Write the operation as one fraction.



Reduce the fraction to lowest term possible