ClassFlow
Class Flow: Goats and Monsters
[Free Registration/Login Required] Students explore methods to measure lengths of squares and radius of a circle in trying to keep a goat from escaping.
University of St. Andrews (UK)
University of St. Andrews: Involute of a Circle
This site, which is provided for by the University of St. Andrews, allows you to zoom in/out and add evolutes, involutes, etc.
University of St. Andrews (UK)
University of St. Andrews: Involute of a Circle
This site from the University of Saint Andrews shows the involute of a circle graphically and gives brief history. Cartesian equation is given.
Rice University
Rice University: Cynthia Lanius: Circles Around Pythagoras
This site from the Rice University includes a fill-in-the-blank lesson on the definition of circles, as Pythagoras described.
Other
Paper Plate Education: Serving the Universe on a Paper Plate
Excellent resource for "paper-plate" activities that help simplify various astronomy topics. Learn how to build a "Moon Finder" and "Planet Pointer," and create a paper-plate model that explains the Transit of Venus.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Pi and the Area of Circles
Contains a question pertaining to finding the area of a circle.
Math Words
Math words.com: Radius of a Circle or Sphere
This site from MathWords.com explains and shows visually what the radius of a sphere is.
Other
Academic Info: Mathematics Gateway
This site provides a comprehensive index and general directory to math sites that will help students in the study of circles.
National Council of Teachers of Mathematics
The Math Forum: Suzanne Alejandre's Designs With Circles
In the Islamic culture, circles are considered to be a unit of measurement and the basis for the organization of space. This is illustrated at this site by a series of exercises.
National Council of Teachers of Mathematics
The Math Forum: Mathematics Teacher Bibliography: Circles
A bibliography of articles relating to circles published in the Mathematics Teacher is listed.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: The Area of a Circle
An investigative approach is given to exploring finding the area of a circle.
Curated OER
Circle Conic
An overview of the four types of conic sections is presented. The origin of how each conic is formed and a table of various characteritics specific to each type of conic is shown.
Curated OER
Visual Calculus: Area of a Circle
Students will be able to use The Method of Exhaustion and find the area of a circle by illustrating graphically.
Curated OER
Research Pages: Circle Inversion Fractals
This site introduces the iteration of circle inversions and describes the associated properties.
Curated OER
Research Pages: Circle Inversion Fractals
This site introduces the iteration of circle inversions and describes the associated properties.
Curated OER
Web Math: Graph a Circle
WebMath offers a java applet that allows you to input information about a circle, in one of four forms, and gies you the graph of the circle.
Curated OER
Lowest Terms With Circles
Practice finding the lowest term name for a variety of different fractions using circles.
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.
Curated OER
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.
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...
Curated OER
Graph Circle (Horiz.)
An overview of the four types of conic sections is presented. The origin of how each conic is formed and a table of various characteritics specific to each type of conic is shown.
Curated OER
Parametric Unit Circle
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...