CK-12 Foundation
Ck 12: Geometry: Circles: Segments and Lengths Study Guide
This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.
Cuemath
Cuemath: Tangent
Learn about the tangent definition in geometry, tangent geometry, tangent to a circle, tangent line equation. Check-out the solved examples for better understanding and try your hand at the tangent line calculator or solving a few...
Oswego City School District
Regents Exam Prep Center: Circles, Segments, and Area
A wealth of resources to supplement instruction on parts of the circle. Find lessons describing chords, tangents, secants, and segments, as well as related practice quizzes and classroom activities.
CK-12 Foundation
Ck 12: Geometry: Properties of a Circle Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews the terminology for circles (tangent, arcs, central angles) and the equation for a circle.
Cuemath
Cuemath: Circles
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
Geometry Help
Geometry Help: Tangent Lines
Explains the basic concept of congruent triangles 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.
Johan Claeys
Math Abundance: The Circle: Basic Concepts
Goes over the equation of a circle, parametric equations of a circle, intersection of circle and line, tangent line in a point of a circle, etc.
Science Buddies
Science Buddies: Tangent Circles and Triangles
Here is a project that combines Computer Science and Mathematics. The two circles are tangent to one another at point A. Their diameters are parallel. Prove that points A, D and F are co-linear. You'll also learn how to create an...
Maths Challenge
Maths challenge.net: Three Circles
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles.
Math Planet
Math Planet: Geometry: Advanced Information About Circles
Provides advanced information about circles through the use of examples and a brief video lesson. [1:00]
Mr. Martini's Classroom
Mr. Martini's Classroom: Circles Geometry Review
This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.
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...
CK-12 Foundation
Ck 12: Geometry: Tangent Lines
[Free Registration/Login may be required to access all resource tools.] This concept teaches students about tangent lines and how to apply theorems related to tangents of circles.
CK-12 Foundation
Ck 12: Interactive Geometry: 8.7 Tangent Lines to Circles
When a line intersects a circle in exactly one point the line is said to be tangent to the circle or a tangent of the circle.
CK-12 Foundation
Ck 12: Geometry: Segments From Secants and Tangents
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to solve for missing segments created by a tangent line and a secant line intersecting outside a circle.
Khan Academy
Khan Academy: Challenge Problems: Radius & Tangent
Solve two challenging problems that apply properties of tangents to find the radius of a circle with a tangent.
Khan Academy
Khan Academy: Tangents of Circles Problems
Solve problems related to tangents of circles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Geometry: Angles Outside a Circle Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate angles formed outside a circle by tangent and secant lines.
Khan Academy
Khan Academy: Determining Tangent Lines: Lengths
Solve two problems that apply properties of tangents to determine if a line is tangent to a circle.
Khan Academy
Khan Academy: Determining Tangent Lines: Angles
Solve two problems that apply properties of tangents to determine if a line is tangent to a circle.
CK-12 Foundation
Ck 12: Geometry: Angles on and Inside a Circle Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to find angles on and inside a circle created by chords and tangent lines.
CK-12 Foundation
Ck 12: Geometry: Parts of Circles
[Free Registration/Login may be required to access all resource tools.] Name the parts of a circle.
CK-12 Foundation
Ck 12: Geometry: Angles on and Inside a Circle
[Free Registration/Login may be required to access all resource tools.] Solve problems containing angles on or inside a circle.