1. Introduction to Radians (Definition, Converting Between Radians and Degrees, & When to use Degrees or Radians)

2. In a Full Circle there are: Radian 1 length of a Radius 1 Radian 2π Radians OR 360° A radian is defined by the angle whose arc length is equal to the length of the radius.radian 2 3 4 5 6 About 0.3

3. Use the following proportion to convert radians to degrees or vice versa: Ex: How many radians are in 240°? Degrees v Radians Radians

4. When to use Degrees or Radians If a problem does not specify to use degrees or radians, then… Use Degrees if the variables or the angles are measured in degrees. For example, use degrees if you have to evaluate: Use Radians if the variables or angles do not have any units or are in terms of Pi. For example use radians if you have to evaluate: