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: 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: Algebra: Sets and Symbols
[Free Registration/Login may be required to access all resource tools.] Classify real numbers as rational numbers, whole numbers, integers, and irrational numbers.
Rice University
Rice University: Cynthia Lanius: History of Geometry
Different cultures' contributions to Geometry are discussed.
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.
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the area of a circle. Students examine guided notes, review guided practice, watch instructional videos and attempt...
Alabama Learning Exchange
Alex: "Introducing Pi!"
The overriding purpose of the lesson is to actively engage students in learning activities that promote opportunities for students to discover the 'meaning' of pi. Activities will include research, hands-on, software applications,...
Shodor Education Foundation
Shodor Interactivate: Buffon's Needle
Experiment with a simulation to get an approximation of Pi by dropping a needle on a lined sheet of paper.
Math Open Reference
Math Open Reference: Circle
Learn about circles with this handy reference guide. Provides a detailed definition, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Cuemath
Cuemath: Irrational Numbers
Learn how to identify irrational numbers. This lesson reviews the irrational number list, the difference between irrational and rational numbers, and whether or not irrational numbers are real numbers. Examples are provided along with a...
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: Area of Circles
Brush up on your math skills relating to the area of circles then try some practice problems to test your understanding.
Quia
Ixl Learning: Pi
Brush up on your math skills relating to pi then try some practice problems to test your understanding.
Better Lesson
Better Lesson: Exploring Circumference
What is pi, anyway? Students explore the relationship between circumference and diameter by measuring a variety of circles and use it to derive the formula for circumference.
Math2
Math2.org: Expansions for Pi
A listing of some of the more famous formulas developed and used throughout the centuries for defining pi are given and explained.
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.
Wolfram Research
Wolfram Math World: Archimedes' Recurrence Formula
This page from Mathworld.com presents illustrations and equations involving Archimedes' Recurrence Formula.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Irrational Pi
Math Forum response to the question of why pi is not rational if it is a ratio of circumference to diameter.
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.
Ducksters
Ducksters: Holidays for Kids: Pi Day
Kids learn about Pi Day. The history and facts about this holiday which celebrates math and the number pi.
Teaching Treasures Publications
Teaching Treasures: Year Eight Nine Math (Measurement)
Display your knowledge of Pythagoras theorem, pi, measurement, and algebra using this interactive worksheet. Answers can be accessed immediately and help links are provided for learners who may have difficulty grasping these concepts....
ClassFlow
Class Flow: Volume of Cylinders
[Free Registration/Login Required] This flipchart guides the students through the process of determining the volume of a cylinder. Students learn to transform formulas in order to find the missing elements.
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...
University of Cambridge
University of Cambridge: Nrich: Watching the Wheels Go `Round and `Round
Use the formula for the circumference of a circle to solve the challenge of this problem. The solution is available at this one page website.