Texas Instruments
Texas Instruments: Circles All Around
This activity provides students an opportunity to explore the relationship between the diameter of a circle and its circumference. [Requires Adobe Reader.]
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
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 radius, diameter, and circumference of different circles. Students examine guided notes, review guided practice, watch...
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]
CK-12 Foundation
Ck 12: Interactive Geometry: 8.2 Area and Circumference of Circles
A deep dive into the area and circumference of circles.
Quia
Ixl Learning: Circumference of Circles
Brush up on your math skills relating to the circumference of circles of measurement then try some practice problems to test your understanding.
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.
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...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate the area of circles and the area of sectors of circles by using given information and formulas. Students examine guided notes,...
Quia
Ixl Learning: Area of Circles
Brush up on your math skills relating to the area of circles then try some practice problems to test your understanding.
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...
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.
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.
Illustrative Mathematics
Illustrative Mathematics: G Gmd Circumference of a Circle
For this task, students are asked to explain the formula for finding the circumference of a circle. Aligns with G-GMD.A.1.
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.
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.
Math Open Reference
Math Open Reference: Circles
A complete reference guide to circles including parts, angles, and arcs. It provides definitions and interactive activities that enhance further explanation.
CK-12 Foundation
Ck 12: Geometry: Inscribed Angles in Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students properties of inscribed angles and how to apply them.
Math Open Reference
Math Open Reference: Parts of a Circle
Learn about parts of a circle with this pictorial index. Click on the diagrams for more information. Includes links to related topics.
Math Open Reference
Math Open Reference: Radius 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.
Math Open Reference
Math Open Reference: Area Enclosed by a Circle
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.
Texas Education Agency
Texas Gateway: Exploring the Ratio of Circumference to Diameter
This activity provides an opportunity for students to explore the ratio of the circumference of its circle to the length of its diameter in order to generalize the ratio of pi. [3:14]
Calculator Soup
Calculator Soup: Circle Calculator
Use this circle calculator to find the area, circumference, radius, or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.