1. Radian Measure and Coterminal Angles
Honors Algebra II with Trigonometry

2. Essential Vocabulary:
Essential Questions: How do I draw angles in standard position? How do I convert between degrees and radian measures? How do I find coterminal angles?
Essential Vocabulary:
Standard Position
Coterminal Angles
Radian Measure

3. Standard Position
An angle is in Standard Position if its vertex is at the origin and its initial side lies on the positive x-axis.
Positive Angles – Counterclockwise Rotation
Negative Angles – Clockwise Rotation

4. Coterminal Angles
Coterminal Angles are angles whose terminal sides coincide.
We can find coterminal angles by adding or subtracting 𝟑𝟔𝟎 ° in degrees or 𝟐𝝅 in radians.

5. Converting Between Degrees and Radians
Angles are measured in Degrees or Radians.
To Convert from Degrees to Radians:
Multiply the degree measure by 𝝅 𝒓𝒂𝒅𝒊𝒂𝒏𝒔 𝟏𝟖𝟎 °
To Convert from Radians to Degrees:
Multiply the radian measure by 𝟏𝟖𝟎 ° 𝝅 𝒓𝒂𝒅𝒊𝒂𝒏𝒔

6. Evaluating Trigonometric Functions from the Unit Circle
Quiz 4 Tomorrow:
Evaluating Trigonometric Functions from the Unit Circle
Ex: 𝑐𝑜𝑠 45° =
(You will not be allowed to use your calculators or look at your Unit Circle during the quiz.)
Homework 9.4