Activity
University of Saskatchewan (Canada)

Finding Arc Length and Central Angle Exercises

For Students 9th - 10th Standards
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....
Handout
Geometry Help

Geometry Help: Arcs, Angles, and Sectors

For Students 9th - 10th Standards
Explains the basic concept of arcs, angles, and sectors with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Unit Plan
Cuemath

Cuemath: Circles

For Students 3rd - 8th Standards
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
Handout
CK-12 Foundation

Ck 12: Geometry: Circles: Segments and Lengths Study Guide

For Students 9th - 10th Standards
This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.
Graphic
Math2

Math2: Circles

For Students 9th - 10th Standards
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
Activity
Math Open Reference

Math Open Reference: Constructions

For Students 9th - 10th Standards
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
Interactive
Mangahigh

Mangahigh: Shape: Circumference of a Circle

For Students 9th - 10th Standards
Determine the circumference of a circle or simple arc lengths.
Activity
Analyze Math

Analyze Math: Sectors and Circles Problems

For Students 9th - 10th Standards
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.
Unit Plan
Khan Academy

Khan Academy: Challenge Problems: Inscribed Angles

For Students 9th - 10th Standards
Solve two challenging problems that apply the inscribed angle theorem to find an arc measure or an arc length.
Unknown Type
Khan Academy

Khan Academy: Inscribed Angles

For Students 9th - 10th Standards
Practice the relationship between inscribed and central angles that are subtended by the same arc length. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unit Plan
Khan Academy

Khan Academy: Challenge Problems: Inscribed Shapes

For Students 9th - 10th Standards
Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.
Handout
Math Open Reference

Math Open Reference: Horizontal

For Students 9th - 10th
Learn about arc length with this handy reference guide. Provides a detailed definition examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Handout
Johan Claeys

Math Abundance: The Circle: Basic Concepts

For Students 9th - 10th Standards
Goes over the equation of a circle, parametric equations of a circle, intersection of circle and line, tangent line in a point of a circle, etc.
Graphic
Curated OER

Circle Picture

For Students 9th - 10th
This site provides definitions for different parts of a circle, pictures to more clearly represent formulas involving circles. Some of the formulas discussed include: area of a circle, area of a sector of a cirles, circumference, length...