Khan Academy
Khan Academy: Area and Parts of Circles
Practice finding the area or circumference of part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Area of Parts of Circles
Practice problems finding area of parts of circles.
Khan Academy
Khan Academy: Area of a Circle
Find the area of a circle given its radius, diameter, or circumference. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: La Circunferencia
In Spanish. In this interactive activity you will get a clear understanding of the definition the circumference of a circle and have fun while learning the relationship between equations and figures.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on Circles
Students show comprehension of advanced mathematics skills in Geometry. The questions check understanding on circles. Topics include diameters, angles, and finding the circumference.
![Top Science: Pi Graph [Pdf] Unknown Type](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "Top Science: Pi Graph [Pdf] Unknown Type")
TOPS Learning Systems
Top Science: Pi Graph [Pdf]
An activity where students explore and graph the relationship between the diameter and the circumference of a circle.
Texas A&M University
Wtamu Virtual Math Lab: Beginning Algebra: Formulas
This tutorial will show you how using formulas can help you solve problems. Include formulas for various geometric shapes and steps showing how to use them.
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.
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.
Wolfram Research
Wolfram Math World: Circumference
This site provides the formula for circumference. Links are provided.
Ducksters
Ducksters: Kids Math: Circle Geometry
Circle Geometry math for kids contains information for students to learn about terms radius, diameter, circumference, chord, and pi.
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.
PBS
Pbs Learning Media: Formulas: Targeted Math Instruction
At the end of this lesson plan about formulas, young scholars will be able to identify and apply the correct formula for a given situation, solve for any unknown component of the formulas for perimeter, circumference, and area of regular...
CK-12 Foundation
Ck 12: Circumference: Ancient Stonehenge Math Mysteries
[Free Registration/Login Required] Students change the length of a radius to explore the circumference of a circle. Click challenge me to answer practice questions and click learn more to watch a video.
Other
Visnos: Explore Pi
This interactive demonstration shows firstly how pi relates to the circumference of a circle. This is achieved using a regular polygon approximation, the closed polygon is opened to reveal this magical number. The area of a circle is...
National Council of Teachers of Mathematics
The Math Forum: Pi Day
Need some ideas for Pi Day on March 14th? You can get some great resources at this location. There are all kinds of links available.
Math Open Reference
Math Open Reference: Diameter
A complete reference guide to diameters. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Arc
Learn about arcs with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Wolfram Research
Wolfram Math World: Pi
This site from Mathworld.com provides a detailed overview of pi. Content includes a diagram, an analysis of its value, how and when pi crops up in mathematics, historical references to pi, and more.
Quia
Ixl Learning: Perimeter
Brush up on your math skills relating to perimeter then try some practice problems to test your understanding.
National Council of Teachers of Mathematics
The Math Forum: Multicultural Math Fair: Srinivasa's Spheres
Straightforward lesson that introduces students to pi by letting them measure real objects and solve a challenge problem. Includes instructions and a "Data Sheet" for keeping track of measurements. Available in English and Spanish.
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.