OER Commons
Oer Commons: Measuring Circles
Seventh graders will measure the circumference and diameter of round things in the classroom and discover the ratio pi. They will see that the ratio of a circle's circumference to its diameter can be used to solve for the circumference...
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...
National Council of Teachers of Mathematics
Nctm: Illuminations: Computing Pi
This resource investigates approximating the value of pi through the calculation of perimeters of inscribed or circumscribed polygons. The interactive tool allows learners to examine and compare both methods.
Lawrence Berkeley National Laboratory
Berkeley Lab: Did You Ever Wonder? Why the Digits of Pi Look Random?
Students investigate the randomness of the digits of pi. The article discusses David Bailey, experimental mathematics, and numerical algorithms. The resource consists of pictures, quotes, and links to additional resources.
University of Regina (Canada)
University of Regina: Math Central: Archimedes's Approximation of Pi
Students explore the process used by Archimedes to approximate pi. The activity enables students' to come to their own approximations of pi when bounded by limits.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: About Pi
This site provides an in-depth discussion on what pi is. It gives a brief history revealing what the Egyptians and Babylonians estimated pi at.
University of Utah
University of Utah: Archimedes and the Computation of Pi
Contains information about the life and works of Archimedes. Includes a Pi applet. Has links to Eratosthenes of Cyrene, A listing of Pi to 10,000 digits, a biography of Archimedes, notes on Pi, and sources on Archimedes' screw.
Texas A&M University
Texas A&m University: Archimedes of Syracuse
This site is provided for by the Texas A&M University. Archimedes contribution to finding the exact value of pi is discussed in this biography of Archimedes.
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 Content includes a diagram, an analysis of its value, how and when pi crops up in mathematics, historical references to pi, and more.
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.
Texas Instruments
Texas Instruments: Approximation of Pi Using Statistical Testing
Students can use a Monte Carlo method to collect data. This data, along with an area model of pi, will be used to approximate pi.
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.
Texas Instruments
Texas Instruments: Discovering Pi
Students will measure the circumference and diameter of round objects. They will send in their measurements through TI-Navigator and discover the relationship between the circumference and diameter.
Texas Instruments
Texas Instruments: 3.14159265
In this activity, students investigate the circumference of circles and learn about the irrational number Pi.
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: 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: 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.
Texas Instruments
Texas Instruments: Approximation of Pi Using Archimedes' Method
Students can use trigonometric ratios to discover the circumference of regular polygons inscribed within and circumscribed about a circle. These ratios will help approximate a value of pi.
Texas Instruments
Texas Instruments: Approximation of Pi Using an Area Model
Students will approximate pi by setting up trigonometric ratios and calculating the areas of regular polygons inscribed within and circumscribed about a circle.
TED Talks
Ted: Ted Ed: Mile of Pi
The team from Numberphile printed one million decimal places of Pi onto a piece of paper which stretched for over a mile. They rolled it out on a runway usually used for testing planes and cars. [6:28]
TED Talks
Ted: Ted Ed: The Infinite Life of Pi
This irrational number, pi, has an infinite number of digits, so we'll never figure out its exact value no matter how close we seem to get. Reynaldo Lopes explains pi's vast applications to the study of music, financial models, and even...
TED Talks
Ted: Ted Ed: Pi With Pies
Numberphile did something crazy - attempted to calculate Pi using real Pies. Watch and see how close they got to the real figure of 3.14159265359. [3:13]
Other
Uc Riverside: Usenet Relativity Faq
A physics usenet listing of frequently asked questions relating to relativity, answered by a number of scientists. Administrivia and Reference, Speed of Light, Special Relativity, General Relativity and Cosmology, Black Holes. Loads of...
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.