Math2
Math2: Circles
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...
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.
Other
Ic Teachers: Shapes, Circles (Basic)
This basic website will give you lots of information about circles. There are also some questions to test your circle knowledge.
CK-12 Foundation
Ck 12: Geometry: Parts of Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students the vocabulary for the parts of circles, including lines passing through circles.
CK-12 Foundation
Ck 12: Geometry: Parts of Circles
[Free Registration/Login may be required to access all resource tools.] Name the parts of a circle.
CK-12 Foundation
Ck 12: Geometry: Inscribed Quadrilaterals in Circles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students properties of inscribed quadrilaterals in circles.
Texas Instruments
Texas Instruments: Radius, Diameter, and Circumference of a Circle
In this activity, students will learn the basic concepts of the circle. They explore the relationship between the diameter and the radius, and between the diameter and circumference of a circle. They also get familiar with the Greek...
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...
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Circle Exercises
Twenty-five problems cover various circle activities. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check each step of your...
Texas Instruments
Texas Instruments: Circle Around
In this activity, students compute the circumference and area of circles. They understand that the ratio of the circumference to the diameter is a value called pi. [Requires Adobe Reader.]
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.
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.