By the end of this section, you will be able to define arc length, rotation angle, radius of curvature, and angular velocity; and to calculate the angular velocity of a car wheel spin.

Recall that a portion of a circle is called an arc. One way to measure an arc is with degrees.

This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.

Here is a site that clearly and thoroughly explains the radian measure of angles. There are example problems solved, problems for the student to attempt, and answers to the student problems.

For this task, students use a piece of string or another tool to measure the radius of the circle and then mark off the corresponding arc length on the unit circle as many times as they need to for 0, 1, 2, 3, 4, 5, and 6 radians. They...

In this activity using the USA TODAY Snapshot, "Coming clean about showering time," students will find the measures of central angles and arcs of a circle. They will use circumference, radius, concentric circles and degrees in a circle...

Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.

Concepts in Trigonometry are explained and illustrated here by a member of the math department at Borough of Manhattan Community College.