1. Trigonometry The science of studying angle measure

2. Angle: two rays with same initial point Initial side Terminal side The measure of an angle is the amount of rotation required to rotate one side, called the initial side, to the other side, called the terminal side.

3. An angle at standard position: if its vertex is at the origin of the rectangular coordinate system and its initial side lies along the positive x- axis Negative: since the angle rotated clockwise Positive: since the angle rotated counterclockwise

4. Degree Measure A Circle can be divided into 360 0

5. 2∏ ∏2∏2 3∏ 2 ∏ Radian Measure

7. Examples: Convert degree to radian measure

8. Convert the following Radian Measure to Degree Convert the following Degree to Radian Measure 2∏ 3 5∏ 6 ∏ 6 3 210 0 135 0 60 0 225 0 =120 0 =150 0 =30 0 =300 0 7∏ 6 3∏ 4 ∏ 3 5∏ 4