Lesson 1 Summary

 

In this lesson you learned that angles can be described using different measures and units. You focused on the relationship between degrees and radians. In Try This 1 you discovered how to describe an angle measure of 1 rad. You used the ratio of the radius and arc length to determine measurements in radians.

 

In Try This 2, Angles in Degrees and Radians helped you find the relationship 360° = 2π rad. Understanding this relationship allows you to convert between radians and degrees using any method.

 

You were able to visualize the following:

• Angles in standard position are positive when the terminal arm rotates counterclockwise.
• Angles in standard position are negative when the terminal arm rotates clockwise.

You applied this understanding in Module 4 Project: The Ferris Wheel to describe the direction of motion of the Ferris wheel.

 

Throughout the rest of Module 4 you will continue to look at objects that move in circular paths, such as amusement park rides. In Lesson 2 you will use the relationship between radians and degrees to explain the distance travelled by an object moving in a circular path.