Lesson 2 Summary

 

In this lesson you looked at objects rotating over and over again. The time-lapse image shows stars rotating around and around, as seen from the North Pole.

 

You learned that coterminal angles have the same terminal arm in standard position. There are an infinite number of coterminal angles for any given angle θ. Coterminal angles can be expressed in general form as θ + (360°)n, n ∈ I or θ + 2πn, n ∈ I.

 

Arc length is related to the radius of the circle and the central angle in radians. You learned that you could use either proportion of the circumference or the formula a = θr to determine arc length.

 

You went around and around in circles in this lesson. In Lesson 3 you will continue to study some of the properties of circles and determine how this information can help you with trigonometry.