Khan Academy
Khan Academy: Circumference of a Circle
Practice finding the circumference of a circle.
Khan Academy
Khan Academy: Circumference of a Circle
Find the circumference of a circle when given either the radius or diameter.Find the radius or diameter of a circle when given the circumference.Students receive immediate feedback and have the opportunity to try questions repeatedly,...
BBC
Bbc: Bitesize Review Circle Introduction
Do you need to learn about Pi, circumference, or the area of a circle or just have a quick refresher about them? This British web site will take you through the basics and offers a quick on-line test to help you check your understanding.
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.
Math Planet
Math Planet: Calculating the Circumference of a Circle
Gain an understanding of how to find the diameter of a circle by viewing an example and a video lesson. [1:01]
Khan Academy
Khan Academy: Area and Circumference of Parts of Circles
In this exercise, students practice find the area and circumference, of parts of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Math Open Reference
Math Open Reference: Circumference (Perimeter) of a Circle
Learn about the circumference of a circle with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
PBS
Pbs Learning Media: Math + Arts: Circle Designs
For 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.
Math2
Math2: Circles
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
Khan Academy
Khan Academy: Circumference and Rotations
Practice these problems with circumference and rotations.
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...
PBS
Pbs Learning Media: Square Wheeled Tricycle: Radius and Circumference
This interactive exercise focuses on working with the radius of various circles to find the circumference and area as well as challenging you to find the distance a square wheel travels around the track.
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.
Quia
Ixl Learning: Area of Circles
Brush up on your math skills relating to the area of circles then try some practice problems to test your understanding.
BBC
Bbc: Circumference and Area of a Circle
This is where you can pick up some valuable pointers on how to find the circumference and area of a circle. There is also information on how to find the perimeter and area of a semicircle. When you finish working your way through the...
Thinkport Education
Math by Design: Circumference and Area of a Circle [Pdf]
Students will discover how to estimate and measure the circumference and area of a circle.
Discovery Education
Discovery Education: Web Math: Find Out Things About Circles
This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Math Open Reference
Math Open Reference: Parts of a Circle
Learn about parts of a circle with this pictorial index. Click on the diagrams for more information. Includes links to related topics.
Illustrative Mathematics
Illustrative Mathematics: G Gmd Area of a Circle
For this task, students investigate and develop an understanding of the formula for the area of a circle. Aligns with G-GMD.A.1.
Math Open Reference
Math Open Reference: Radius of a Circle
Learn about the radius of a circle with this useful reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Area Enclosed by a Circle
A complete reference guide to the area enclosed by a circle. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.