CK-12 Foundation
Ck 12: Interactive Geometry: 8.8 Secant Lines to Circles
Learn about a line that intersects a circle in two points is called a secant line.
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.
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.
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.
Texas Education Agency
Texas Gateway: Making Conjectures About Circles and Segments
Given examples of circles and the lines that intersect them, the student will use explorations and concrete models to formulate and test conjectures about the properties and relationships among the resulting segments.
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.
Other
Ctte: Geometer's Sketch Pad Activities
This site offers numerous activities for middle school and high school learners to explore using Geometer's Sketch Pad.