Unit 7, Lesson 3
The Unit Circle (Part 1)
Algebra 2
Practice
Problem 1
\(C\) is a circle with radius \(r\). Which of the following is true? Select all that apply.
The diameter of \(C\) is \(2r\).
The circumference of \(C\) is \(\pi r\).
The circumference of \(C\) is \(2\pi r\).
One-quarter of the circle has length \(\frac{\pi r}{4}\).
One-quarter of the circle has length \(\frac{\pi r}{2}\).
Problem 2
The table shows an angle measure in radians and the amount of rotation about a circle corresponding to the angle. For example, \(2\pi\) radians corresponds to 1 full rotation. Complete the table.
| angle measure | rotation |
|---|---|
| 0 | 0 |
| \(\frac{\pi}{6}\) | |
| \(\frac{1}{8}\) | |
| \(\frac{1}{6}\) | |
| \(\frac{\pi}{2}\) | |
| \(\frac{2\pi}{3}\) | |
| \(\frac{1}{2}\) | |
| \(\frac{3\pi}{2}\) | |
| \(\frac{7}{8}\) | |
| 1 |