Math Planet
Math Planet: Calculating the Circumference of a Circle
Gain an understanding of how to find the diameter of a circle by viewing an example and a video lesson. [1:01]
Math Open Reference
Math Open Reference: Circumference (Perimeter) of a Circle
Learn about the circumference of a circle with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Better Lesson
Better Lesson: Exploring Circumference
What is pi, anyway? Students explore the relationship between circumference and diameter by measuring a variety of circles and use it to derive the formula for circumference.
Math Open Reference
Math Open Reference: Diameter
A complete reference guide to diameters. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Khan Academy
Khan Academy: Radius and Diameter
Practice problems finding radius and diameter of a circle.
BBC
Bbc: Circumference and Area of a Circle
This is where you can pick up some valuable pointers on how to find the circumference and area of a circle. There is also information on how to find the perimeter and area of a semicircle. When you finish working your way through the...
PBS
Pbs Learning Media: Math + Arts: Circle Designs
In this lesson, students explore circumference and diameter by creating an abstract design with circles. Media resources and teacher materials are included.
Khan Academy
Khan Academy: Radius and Diameter
Practice finding the radius and diameter of a circle using both vocabulary and visuals. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
TeachEngineering
Teach Engineering: Let's Take a Slice of Pi
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...
CK-12 Foundation
Ck 12: Geometry: Diameter or Radius of a Circle Given Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the diameter or radius of a circle given the circumference. Students examine guided notes, review guided practice, watch instructional...
CK-12 Foundation
Ck 12: Geometry: Diameter or Radius of a Circle Given Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the diameter or radius of a circle given its circumference. Students examine guided notes, review guided practice, watch instructional...
CK-12 Foundation
Ck 12: Geometry: Circle Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the circumference of a circle given the radius or the diameter. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Circle Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the circumference of a circle given its diameter or radius. Students examine guided notes, review guided practice, watch instructional...
CK-12 Foundation
Ck 12: Geometry: Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate a circle's circumference. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
CK-12 Foundation
Ck 12: Geometry: Circumference
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the circumference of a circle. Students examine guided notes, review guided practice, watch instructional videos and...
Math Is Fun
Math Is Fun: Definition of Circumference
Definition of circumference. Click the "here's more" link to learn more about a circle; its radius and diameter, area, lines, slices and common sectors.
Other
Circles/circumference Interactive Learning Sites for Education
Includes record sheets and interactive media exploring circles and circumference from general parts of the circle to the relationship of the circle parts.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Circles
Get independent practice working with finding the circumference, area and radius of circles. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
PBS
The Math of Bicycles: Wheel Figure This Out (Grades 4 7)
Several good activities here. Look particularly at Wheel Figure It Out (which is the opening page) and Gearing Up. There are answers to the very good questions at the bottom of each.
Texas Instruments
Texas Instruments: Looking at Statistics Through Circles
In this activity, students will measure round objects to determine the circumference and diameter, and use the data to explore geometric concepts of the circle with statistics.
TOPS Learning Systems
Top Science: Pi Graph [Pdf]
An activity where students explore and graph the relationship between the diameter and the circumference of a circle.
Khan Academy
Khan Academy: Praxis Core Math: Circles Lesson
A basic review of circles and how to calculate the circumference, radius, diameter, and area. Includes practice questions.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on Circles
Students show comprehension of advanced mathematics skills in Geometry. The questions check understanding on circles. Topics include diameters, angles, and finding the circumference.
Discovery Education
Discovery Education: Web Math: Find Out Things About Circles
This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.