Wolfram Research
Wolfram Math World: Radius
This math site from MathWorld.com defines radius in terms of both a circle and a sphere. The site includes a diagram and links to related topics.
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.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Diameter,circumference,radius & the Discovery of Pi
This site provides a good project for young scholars to use to explore the circumference of a circle.
Math Words
Math words.com: Foci of an Ellipse
The definition for foci for an ellipse is given and the definition for ellipse is given. Also gives a diagram and the equation for an ellipse in standard form.
Math Is Fun
Math Is Fun: Definition of Circumference
Definition of circumference. Click the "here's more" link to learn more about a circle; its radius and diameter, area, lines, slices and common sectors.
Mr. Martini's Classroom
Mr. Martini's Classroom: Volume: Geometry Practice Solving Volumes
Students solve for the volume of three-dimensional figures such as cubes, prisms, and cylinders with these interactive flashcards.
Other
Research Pages: Circle Inversion Fractals
This site introduces the iteration of circle inversions and describes the associated properties.
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 Flash Cards
Do you need practice remembering or learning different geometry vocabulary words and definitions? The flash cards at this web site are for you! There is a link to a list of terms with definitions you can click if you want to see if you...
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...
Quia
Quia: Geometric Terms Word Search
Do you need practice remembering or learning different geometry vocabulary words and definitions? This word search 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 you are...
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.
ClassFlow
Class Flow: Spheres Geometry
[Free Registration/Login Required] In this flipchart, students develop an understanding of the properties of a sphere and determine its area and volume.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Radius
Find a quick, concise explanation of what a radius is. An example is given and clearly explained.
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...
ClassFlow
Class Flow: Circle Vocabulary
[Free Registration/Login Required] This lesson lets students identify, draw, and measure parts of a circle. The lesson compliments 5th grade Harcourt Math, Lesson 23.4. Activote assessment is included at the end of the lesson.
ClassFlow
Class Flow: Circles Geometry
[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.
ClassFlow
Class Flow: Dimensions
[Free Registration/Login Required] Students learn what surface area is on geometric figures, and find volume, lengths, and areas of figures.
Sophia Learning
Sophia: Determining Unknown Values Using the Volume of a Cylinder
This video lesson demonstrates how to work backward and use the volume of a cylinder to find an unknown value such as the radius or height. Students can check their understanding with an assessment. [4:41]
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.
Free Math Help
Free Math Help: Completing the Square in Circle Equations
This discussion examines how to complete the square in circle equations. Students learn about the math concept through definitions and examples with detailed solutions.
Integrated Publishing
Integrated Publishing: The Wheel & Axle
A solid chapter explanation of the wheel & axle simple machine. Examples, the basic math, explanation of mechanical advantage, drawings, solved problem. Use the Next button. There are four pages in this chapter.