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.
Math Is Fun
Math Is Fun: Pi
Explains what Pi is and how it is calculated. Gives suggestions for how to calculate it yourself and a tip for remembering it to nine decimal places. Includes a set of practice questions.
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]
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...
Texas Education Agency
Texas Gateway: Exploring the Ratio of Circumference to Diameter
This activity provides an opportunity for students to explore the ratio of the circumference of its circle to the length of its diameter in order to generalize the ratio of pi. [3:14]
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
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.
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 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.
Calculator Soup
Calculator Soup: Hemisphere Calculator
This online calculator will calculate the various properties of a hemisphere given any 1 known variable. It also calculates the variables in terms of PI.
Calculator Soup
Calculator Soup: Sphere Calculator
This online calculator will calculate the 3 unknown values of a sphere given any 1 known variable including radius r, surface area A, volume V and circumference C. It will also give the answers for volume, surface area, and circumference...
Calculator Soup
Calculator Soup: Circular Cylinder Calculator
This online calculator will calculate the various properties of a cylinder given 2 known values. It will also calculate those properties in terms of PI.
Calculator Soup
Calculator Soup: Trigonometric Functions Calculator
This online trigonometry calculator will calculate the sine, cosine, tangent, cotangent, secant and cosecant of values. The trigonometric functions are also known as the circular functions.
BBC
Bbc: Bitesize Review Circle Introduction
Do you need to learn about Pi, circumference, or the area of a circle or just have a quick refresher about them? This British web site will take you through the basics and offers a quick on-line test to help you check your understanding.
Oswego City School District
Regents Exam Prep Center: Irrational Approximations
Providing one lesson, one practice exercise, and two teacher resources, the information at this website is geared toward students who already understand rational and irrational numbers. The lesson has explanations of what happens when a...
TeachEngineering
Teach Engineering: How Far Does the Robot Go?
Students practice their multiplication skills using robots with wheels built from LEGO MINDSTORMS NXT kits. They brainstorm distance travelled by the robots without physically measuring distance and then apply their math skills to...
Curated OER
Science Kids: Science Images: Basic Calculator
This photo shows a basic calculator sitting on a desk. The value of Pi is written to five decimal places on the screen.
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,...
CK-12 Foundation
Ck 12: Geometry: Circumference
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate a circle's circumference. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
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.] This concept teaches students how to calculate the area of a circle. Students examine guided notes, review guided practice, watch instructional videos and attempt...
Annenberg Foundation
Annenberg Learner: Math in Daily Life: Home Decorating
This exhibit is designed to show students that geometry really does apply to the real world. By taking viewers through a home decoration project, students learn how to calculate area of a rectangle and circle.