1. 4.2 Degrees and Radians Objectives: Convert degree measures of angles to radian measures Use angle measures to solve real-world problems

2. Degrees and Radians

3. Angles An angle is a measure of the amount of rotation between two line segments. The 2 line segments are called the initial side and terminal side. Angles are measured in degrees and radians.

4. Standard Position If the angle’s vertex is at the origin of the plane and the initial side lies along the positive x-axis, the the angle is said to be in standard position.

5. Quadrantal angles Quadrantal angles are angles in standard position whose terminal ray lies along one of the axes.

6. Positive vs. Negative Angles

7. Let’s draw each angle.

10. Radians Radians are based on the measurement of the circumference of a circle. Radians are used in many science and engineering applications.

11. Degree/Radian Conversion

12. Coterminal Angles Coterminal angles are angles in standard position that have common terminal side but different measures.

15. Find one positive and one negative coterminal angle and draw.