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.
PBS
Pbs Learning Media: Math + Arts: Circle Designs
In this lesson, students explore circumference and diameter by creating an abstract design with circles. Media resources and teacher materials are included.
Khan Academy
Khan Academy: Praxis Core Math: Circles Lesson
A basic review of circles and how to calculate the circumference, radius, diameter, and area. Includes practice questions.
Other
Allmath: Math Glossary
Are your students having difficulty understanding math terminology? Try this A-Z glossary on math related terms. It's quick, easy to read, and very complete.
CK-12 Foundation
Ck 12: Circumference Medium Circle and Circle Units
[Free Registration/Login Required] Students will determine the circumference of circles by moving smaller circle units. Click challenge me to answer practice questions and click learn more to watch a video.
Khan Academy
Khan Academy: Radius and Diameter
Practice problems finding radius and diameter of a circle.
Khan Academy
Khan Academy: Arc Length
Relate the length of an arc to the circumference of a whole circle and the central angle subtended by the arc. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
ClassFlow
Class Flow: Circles and Angles
[Free Registration/Login Required] In this flipchart students practice identifying parts of a circle, measure angles, and practice solving area and circumference problems.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Circumference and Area of Circles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of finding the circumference and area of circles.
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.]
Common Core Sheets
Common Core Sheets: Geometry 8.g.3 Worksheets: Coordinate Plane
Worksheets provide practice with finding the area or circumference of a circle and answer keys are provided. You can even create your own worksheet or flashcards.
Illustrative Mathematics
Illustrative Mathematics: F if Model Airplane Acrobatics
In this task, a model airplane pilot is practicing flying her airplane in a big loop for an upcoming competition. The task could serve as an introduction to periodic functions and as a lead-in to sinusoidal functions. By visualizing the...
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...
ClassFlow
Class Flow: Cylinder Volume
[Free Registration/Login Required] This flipchart contains activities and instructions for students on how to solve for the volume of a cylinder and finding the circumference of a circle.
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.
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.
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.
Cuemath
Cuemath: Radius
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.
The Math League
The Math League: Area and Perimeter
This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.
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.
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.
Homeschool Math
Homeschool Math: Circles
Lesson presents definitions of terms associated with circles and helps students learn to use a compass to draw circles and simple circle designs.
Curated OER
Circle Picture
This site provides definitions for different parts of a circle, pictures to more clearly represent formulas involving circles. Some of the formulas discussed include: area of a circle, area of a sector of a cirles, circumference, length...
Khan Academy
Khan Academy: Radius and Diameter
Practice finding the radius and diameter of a circle using both vocabulary and visuals. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.