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.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
E-learning for Kids
E Learning for Kids: Math: Market Place: 2 D Shapes and Patterns
On this interactive site, students learn to identify squares, circles, and triangles.
Other
Nearpod: Circles & Pi
In this lesson, 7th graders will learn vocabulary associated with circles and use formulas to find the area and circumference of circles.
E-learning for Kids
E Learning for Kids: Math: World of Fish: Geometry
Students will play an interactive game to identify the circumference, radius, center, and diameter of circles.
Government of Alberta
Learn Alberta: Mathematics Glossary: Circle
Get a visual and animated definition of the term "circle" from LearnAlberta.ca's Mathematics Glossary, as well as examples of circles in the real world.
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: Conic Sections/circles
This site provides a catalog of Web sites and Web pages that deal with circles.
Wolfram Research
Wolfram Math World: Circles
This site provides definitions for a wide range of topics dealing with circles.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Degrees in a Circle
Dr. Math answers a students question as to why a circle contains 360 degrees.
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.
Math Words
Math words.com: Conic Sections
Examples of conic sections are given and the equation for their standard form is also given.
Mr. Martini's Classroom
Mr. Martini's Classroom: Teacher's Figure Library: Geometric Figures
This interactive resource provides an example picture of the geometric figure chosen by students to review.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Circunferencia Y Circulo: Longitudes Y Areas
Reinforce your knowledge of the circumference and the area of a circle with these activities. [Requires Java.]
Purple Math
Purplemath: Conics: Circles: Introduction & Drawing
A reference site that gives definitions, examples, explanation of circle attributes and drawing circles in a coordinate plane.
Other
Circles/circumference Interactive Learning Sites for Education
Includes record sheets and interactive media exploring circles and circumference from general parts of the circle to the relationship of the circle parts.
Quia
Quia: Geometric Terms Concentration
Do you need practice remembering or learning different geometry vocabulary words and definitions? This concentration game is the web site for you! There is a link to a list of terms with definitions you can click if you want to see if...
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.
Sophia Learning
Sophia: Two Lines Tangent to a Circle: Lesson 3
This lesson will present how if two segments from the same point outside a circle are tangent to a circle, then they are congruent. It is 3 of 5 in the series titled "Two Lines Tangent to a Circle."
ClassFlow
Class Flow: Reading Circle Graphs
[Free Registration/Login Required] Students are asked to figure out the size of the shaded portions of a circle graph. They then complete a chart showing the fraction, decimal, and percentage equivalents.
ClassFlow
Class Flow: Shapes
[Free Registration/Login Required] This flipchart is designed for an early childhood classroom and focuses on circles, squares, rectangles, and triangles. Opportunities provided for student participation include drawing plane shapes,...
ClassFlow
Class Flow: Algebra, Geometry Conic Review
[Free Registration/Login Required] Flipchart helps student to interpret algebraic equations and inequalities, geometry (cones, spheres, parabolas, etc.) and describes geometric relationships algebraically.