Government of Alberta
Learn Alberta: Exploring the Diameter and Circumference
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.
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...
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.
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.
Ducksters
Ducksters: Kids Math: Circle Geometry
Circle Geometry math for kids contains information for students to learn about terms radius, diameter, circumference, chord, and pi.
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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.
Texas Instruments
Texas Instruments: Approximation of Pi
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.
BBC
Bbc: Bitesize: Maths: 2 D Shapes
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.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Diameter,circumference,radius & the Discovery of Pi
This site provides a good project for students to use to explore the circumference of a circle.
ClassFlow
Class Flow: Area of a Circle
[Free Registration/Login Required] This flipchart reviews basic geometric forms in nature and real objects. Students are then given opportunities to find the area of circle and parts of a circle, given the radius and/or diameter of the...
Learning Wave Communications
Learning Wave: Geometry, Section 2
Geometry concepts are briefly discussed at this site, including volume of a cylinder, parallelograms, circles, trapezoids, and triangles. Sample problems and applications are included for practice.
University of Texas at Austin
Mathematics Teks Toolkit: Exploring C/d= Pie
A collection of circular objects will be used to explore circumference and diameter of circles.
Texas Instruments
Texas Instruments: Predicting Pi
In this activity, students explore the use of linear measurement and calculators to discover the existence of pi, the constant ratio between the circumference and the diameter of a circle.
CK-12 Foundation
Ck 12: Pi
[Free Registration/Login Required] Students will determine Pi by exploring the points on a circle. Click challenge me to answer practice questions and click learn more to watch a video.
Cuemath
Cuemath: Radius
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.
CK-12 Foundation
Ck 12: Geometry: Arc Length
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find the length of an arc. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
Other
Simple Science: Slice of Pi
The interactive tutorial explores the history behind Pi and how to find its value. Students use images of circular objects and find the diameter and circumference to obtain an approximate value of Pi. The resource has an interactive...
Alabama Learning Exchange
Alex: Circling Around
Learners will calculate the diameter, circumference, and ratio of a real world object. Students will create an electronic slideshow to illustrate the process of determining the diameter, circumference, and ratio of these objects.
Wolfram Research
Wolfram Math World: Pi
This site from Mathworld.com provides a detailed overview of pi. Content includes a diagram, an analysis of its value, how and when pi crops up in mathematics, historical references to pi, and more.
Quia
Ixl Learning: Pi
Brush up on your math skills relating to pi then try some practice problems to test your understanding.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Geometry in the Plane
Twenty-four problems presented on a variety of Plane Geometry topics. 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...
Curated OER
Web Math: Find Out Things About Circles
WebMath offers a great site for students to practice finding the diameter, area and circumference of a circle.
National Council of Teachers of Mathematics
The Math Forum: Multicultural Math Fair: Srinivasa's Spheres
Straightforward lesson that introduces learners to pi by letting them measure real objects and solve a challenge problem. Includes instructions and a "Data Sheet" for keeping track of measurements. Available in English and Spanish.
National Council of Teachers of Mathematics
The Math Forum: Pi Day
Need some ideas for Pi Day on March 14th? You can get some great resources at this location. There are all kinds of links available.