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: Polar Area
A complete reference guide to polar area. It provides definitions, examples. and an interactive activity that enhances further explanation. Includes links to related topics.
Geometry Help
Geometry Help: Chords
Explains the basic concept of chords with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Circles
Explains the basic concept of circles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
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: Thales' Theorem
Learn about Thales' Theorem with this handy 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: Polar Derivatives
Learn about polar derivatives with this helpful reference tool. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Incircle
A complete reference guide to incircles. It provides definitions and examples that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Tangent
Learn about tangents with this handy reference guide. Provides detailed definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
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: Circle
Learn about circles with this handy reference guide. Provides a detailed definition, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Secant
Learn about secants with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Congruent
Learn about congruent with this handy reference guide. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
Khan Academy
Khan Academy: Graph a Circle From Its Expanded Equation
Given the expanded equation of a circle, graph the circle.
Khan Academy
Khan Academy: Graph a Circle From Its Standard Equation
Given the standard form equation of a circle, graph the circle.
Khan Academy
Khan Academy: Graph a Circle From Its Features
Given information about the center and radius of a circle, graph it.
Khan Academy
Khan Academy: Points Inside/outside/on a Circle
Given the center and radius of a circle, determine if a point is inside of the circle, on the circle, or outside of the circle.
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.
Math Open Reference
Math Open Reference: Angle Measure of an Arc
Learn about the angle measure of an arc with this handy reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
CK-12 Foundation
Ck 12: Interactive Geometry: 10.2 Equations of Circles
Derive the equation of a circle with the help of the Pythagorean Theorem.
Khan Academy
Khan Academy: Radians & Arc Length
Solve problems related to radians and arc length like finding an arc length given the central angle and radius.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.8 Circles
Understand circles and their measurement applications.
Quia
Ixl Learning: Pi
Brush up on your math skills relating to pi 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.