Khan Academy
Khan Academy: Line and Angle Proofs
Explore different ways of proving some theorems about lines and angles. Some transformations are used. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Khan Academy
Khan Academy: Classifying Shapes by Line and Angle Types
In this exercise, students practice classifying shapes by line and angle types. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Geometry Help
Geometry Help: Intersecting Lines and Angles
Explains the basic concept of intersecting lines and angles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Annenberg Foundation
Annenberg Learner: Geometry: Circles: Inscribed Angles
Study inscribed angles in semicircles and quarter-circles. What conjectures can you make about the measure of an inscribed angle in semi- or quarter-circles?
Analyze Math
Analyze Math: Parallel Lines and Angles Problems
Try these three problems about finding the measures of different angles that arise from diagrams involving parallel lines and transversals. Detailed solutions are written out for these three problems of moderate difficulty.
CK-12 Foundation
Ck 12: Geometry: Alternate Interior Angles
[Free Registration/Login may be required to access all resource tools.] Use alternate interior angles to determine angle congruency and the presence of parallel lines.
CK-12 Foundation
Ck 12: Geometry: Alternate Exterior Angles
[Free Registration/Login may be required to access all resource tools.] Use alternate exterior angles to determine congruency and the presence of parallel lines.
CK-12 Foundation
Ck 12: Geometry: Alternate Exterior Angles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to alternate exterior angles and how to use them to determine whether or not lines are parallel.
Other
800score: Intersecting Angles
Read a description of intersecting lines and all about the different kinds of angles they form. Includes examples.
Oswego City School District
Regents Exam Prep Center: Geometry Vocabulary Resources
A list of geometry definitions and a matching activity.
Oswego City School District
Regents Exam Prep Center: Parallel Lines
Material to supplement classroom instruction on parallel lines: a lesson on angles with parallel lines, a practice quiz, and a link to an investigation on angles with parallel and non-parallel lines.
CK-12 Foundation
Ck 12: Geometry: Alternate Interior Angles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to alternate interior angles and how to use them to determine whether or not lines are parallel.
CK-12 Foundation
Ck 12: Perpendicular Lines
[Free Registration/Login Required] Students explore the concept of perpendicular lines by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...
CK-12 Foundation
Ck 12: Geometry: Same Side Interior Angles
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to same side interior angles and how to use them to determine whether or not lines are parallel.
CK-12 Foundation
Ck 12: Geometry: Parallel and Perpendicular Lines
[Free Registration/Login may be required to access all resource tools.] Identifying types of lines as parallel lines, perpendicular lines or intersecting lines.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Geometry in the Plane
Twenty-four problems presented on a variety of Plane Geometry topics. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check...
Government of Alberta
Learn Alberta: Math Interactives: Exploring Circle Geometry Properties
Investigate circles, namely their angles, chords, and tangents using this highly interactive Learn Alberta math. Explore a number of circle geometry properties that can be used to determine unknowns. Be sure to follow the link to the...
Khan Academy
Khan Academy: Angle Relationships With Parallel Lines
Find missing angles given two parallel lines and a transversal. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Khan Academy
Khan Academy: Equation Practice With Angles
In this practice activity, students calculate angles created when two parallel lines are intersected by a transversal. Students receive immediate feedback and have the opportunity to watch a video, get hints, or try questions repeatedly.
Khan Academy
Khan Academy: Finding Angle Measures Between Intersecting Lines
Practice finding angle measures between intersecting lines.
ClassFlow
Class Flow: Parallel Lines and Angle Relationships
[Free Registration/Login Required] Explore the relationships between parallel lines and the rules of angle measurements.
ClassFlow
Class Flow: Parallel Lines and Angles
[Free Registration/Login Required] This flipchart regards parallel lines and relationship of angles created by a transversal. Includes lesson on vocabulary, Jeopardy-style game, and quiz.
Geometry Help
Geometry Help: What Are Parallel Lines in Geometry?
Explains the basic concept of parallel lines in Geometry with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
CK-12 Foundation
Ck 12: Geometry: Corresponding Angles
[Free Registration/Login may be required to access all resource tools.] In this lesson students identify corresponding angles formed when a line intersects two other lines. Students examine guided notes, review guided practice, watch...