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.
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...
Mathigon
Mathigon: Geometry: Circle and Pi: Introduction
This lesson focuses on the characteristics of a circle including similarity, radius, circumference, and Pi. It provides formulas to determine the area of a circle, calculating Pi, and learning exercises throughout.
CK-12 Foundation
Ck 12: Geometry: Area of Sectors and Segments
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a sector or segment. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the area of a circle. Students examine guided notes, review guided practice, watch instructional videos and attempt...
CK-12 Foundation
Ck 12: Geometry: Circles in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to graph circles and find the standard equations of circles. Students examine guided notes, review guided practice, watch...
Alabama Learning Exchange
Alex: Talking in Circles
The students will identify parts of the circle including center, radius, diameter, chord, and arc. This lesson plan was created by exemplary Alabama Math Teachers through the AMSTI project.
Khan Academy
Khan Academy: Angular and Tangential Acceleration
A site for students to "practice thinking about the relationships between angular acceleration, tangential acceleration, and radius".
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.
National Council of Teachers of Mathematics
Nctm: Illuminations: Power of a Point
Use this tool to investigate what happens when point P is moved to various points within, on, and outside the circle. Can you identify any relationships among the segments and radius?
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.
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.
Cuemath
Cuemath: Radius
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.
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: Area of a Regular Polygon
A complete reference guide to the area of a regular polygon. It provides definitions, 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.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.8 Circles
Understand circles and their measurement applications.
Quia
Ixl Learning: Circumference of Circles
Brush up on your math skills relating to the circumference of circles of measurement then try some practice problems to test your understanding.
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.
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.
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.
Purple Math
Purplemath: The Unit Circle
Relates the unit circle to the method for finding trig ratios in any of the four quadrants. Demonstrates how the unit circle might be useful.
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.