[Free Registration/Login Required] Students use the points on a circle to explore circumference and radius. Click challenge me to answer practice questions and click learn more to watch a video.

[Free Registration/Login Required] Students change the length of a radius to explore the circumference of a circle. Click challenge me to answer practice questions and click learn more to watch a video.

Students show comprehension of advanced mathematics skills in Geometry. The questions check understanding on circles. Topics include diameters, angles, and finding the circumference.

In this lesson plan, 7th graders use their knowledge of formulas to determine the area and circumference of a circle.

Learn about the radius of a circle with this useful reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

A complete reference guide to the area enclosed by a circle. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

This interactive demonstration shows firstly how pi relates to the circumference of a circle. This is achieved using a regular polygon approximation, the closed polygon is opened to reveal this magical number. The area of a circle is...

This multimedia site offers a beginner's guide to understanding the relationship between the diameter and circumference of a circle. This Learn Alberta site offers a video [1:44], interactive exercises and printable extended exercises.

Discusses the radius, diameter, circumference, and area of a circle.

Circle Geometry math for kids contains information for students to learn about terms radius, diameter, circumference, chord, and pi.

In Spanish. In this interactive activity you will get a clear understanding of the definition the circumference of a circle and have fun while learning the relationship between equations and figures.

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...

An activity where students explore and graph the relationship between the diameter and the circumference of a circle.

Students will play an interactive game to identify the circumference, radius, center, and diameter of circles.

Students will measure the circumference and diameter of a variety of different circles. They will graph the class' values of (d,c) on the coordinate plane and use linear regression to approximate pi.

This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.

Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.

Includes record sheets and interactive media exploring circles and circumference from general parts of the circle to the relationship of the circle parts.

[Free Registration/Login Required] This flipchart has information and practice regarding finding area and circumference of circles.

[Free Registration/Login Required] In this flipchart students practice identifying parts of a circle, measure angles, and practice solving area and circumference problems.

Working as a team, students discover that the value of pi (3.1415926) is a constant and applies to all different sized circles. The team builds a basic robot and programs it to travel in a circular motion. A marker attached to the robot...

Relate the length of an arc to the circumference of a whole circle and the central angle subtended by the arc. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Practice problems finding radius and diameter of a circle.

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...