Khan Academy
Khan Academy: Radius and Diameter
Practice problems finding radius and diameter of a circle.
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...
Texas Instruments
Texas Instruments: Exploing Relatioship Between Radius, Area, and Circumference
Visually explore relationships in area and circumference
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.
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...
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...
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]
Khan Academy
Khan Academy: Radius, Diameter, and Circumference
In this exercise, students practice finding radius, diameter, and circumference. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
CK-12 Foundation
Ck 12: Circumference vs. Radius
[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.
CK-12 Foundation
Ck 12: Circumference: Ancient Stonehenge Math Mysteries
[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.
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.
Mathigon
Mathigon: Geometry: Circle and Pi: Introduction
This lesson focuses on the characteristics of a circle including similarity, radius, circumference, and Pi. It provides formulas to determine the area of a circle, calculating Pi, and learning exercises throughout.
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.
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
A lesson focusing on the area of polygons and the circumference of circles. Engaging, interactive practice worksheet, lesson plan, and related classroom activity complete this lesson.
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.
Wolfram Research
Wolfram Math World: Circle
This site from Mathworld provides a wealth of information about circles is presented. The information ranges from the basics--radius, circumference, etc.--to advanced concepts--equations in polar and pedal coordinates, etc.
National Council of Teachers of Mathematics
The Math Forum: The Cylinder Problem: High School Lesson
Using an engaging approach, this lesson requires students to record the volume of cylinders as a function of the radius. Students will construct and measure the volume of several cylinders and then begin comparing these shapes.
CK-12 Foundation
Ck 12: Geometry: Pi
[Free Registration/Login may be required to access all resource tools.] Identify pi as the ratio of a circle's diameter to a circle's circumference.
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...
Maths Challenge
Maths challenge.net: Curvature of the Earth
Distance problem using a spherical radius and height.
Texas Instruments
Texas Instruments: Direct Variation With Powers: Surface Area and Volume
Students find the approximate surface area and volume of an apple, measuring circumference 3 ways, using the mean of the measurements to find the radius. Each students enters the results in a Table on the board.