### Home > PC > Chapter 4 > Lesson 4.1.1 > Problem4-1

4-1.

First, recall some facts that you should remember from Chapter 1.

1. How many radians are in a full circle?

What is the ratio of the circumference of a circle to its radius?

2. How many radians are in half a circle?

1. What are the radian measures that correspond to the following degree measures?

1. $30º$

1. $45º$

1. $60º$

Review your work from problem 1-111.