Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Analyze Math
Analyze Math: Sectors and Circles Problems
Try these three problems regarding area of sectors, length of arcs, and central angles. The problems will challenge and intrigue sharp geometry students. Detailed written solutions are included.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Circles
Practice using your graphing calculator for drawing circles and for finding measurements for circles and parts of the circle. If you get stumped or if you would like to check your work, then select the View Solution button, which is...
CK-12 Foundation
Ck 12: Geometry: Circles: Segments and Lengths Study Guide
This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.
Texas Instruments
Texas Instruments: Math Today Coming Clean About Showering Time
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...
Math Open Reference
Math Open Reference: Constructions
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
Lawrence Hall of Science
The Math Page: Trigonometry: Radian Measure
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.
University of Saskatchewan (Canada)
Finding Arc Length and Central Angle Exercises
This site provides two geometry problems involving circles. One problem has the reader find the arc length given the angle and radius, the other problem has the reader find the measure of the angle given the arc length and radius....
Khan Academy
Khan Academy: Challenge Problems: Inscribed Shapes
Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.
Illustrative Mathematics
Illustrative Mathematics: F Tf.1 What Exactly Is a Radian?
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...
Math Open Reference
Math Open Reference: Sector
Learn about sectors with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.