National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math Alternate Exterior Angles
Dr. Math at the Math Forum offers a way of remembering alternate exterior and alternate interior angles by looking at the words and realize what they say and apply it to the picture.
Math Open Reference
Math Open Reference: Angles
Everything you wanted to know about angles and more, including 1) how to measure angles 2) types of angles 3) angle relationships and 4) angles around a transversal.
Math Words
Math Words: Alternate Interior Angles
This site offers a definition for alternate interior angles with a labeled graph and links to other related words.
CK-12 Foundation
Ck 12: Geometry: Angles and Transversals Study Guide
This study guide on angles and transversals covers key terms, angle types formed by transversals, postulates and theorems about transversals, and how to prove if lines are parallel or perpendicular. It is available for download with free...
Shodor Education Foundation
Shodor Interactivate: Angles
This activity from Shodor Education Foundation will help you learn or review your angle vocabulary.
CK-12 Foundation
Ck 12: Interactive Geometry: 4.2 Theorems About Lines and Angles
Consider two parallel lines that are intersected by a transversal, and when it crosses the two others, many different angle pairs are formed. See the special properties of the angle pairs in this interactive.
Math Open Reference
Math Open Reference: Parallel Lines
Get the definition for parallel lines and explore angles associated with parallel lines.
Government of Alberta
Learn Alberta: Math Interactives: Exploring Parallel Lines (Object Interactive)
Investigate vertically opposite, corresponding, and alternate angles formed by parallel lines and a transversal using this highly interactive Learn Alberta math. Be sure to follow the link to the printable activities, solutions, learning...
University of Georgia
University of Georgia: Inter Math: Exterior Angles
Intermath Dictionary's site defines terms relating to angles, gives examples, and offers interactive exercises.
Mr. Martini's Classroom
Mr. Martini's Classroom: Geometry Special Angle Pairs and Parallel Transversals
Students are challenged to identify and measure angles created by parallel lines and a transversal as well as complementary and supplementary pairs.
Khan Academy
Khan Academy: Finding Angle Measures Between Intersecting Lines
Practice finding angle measures between intersecting lines.
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.
Illustrative Mathematics
Illustrative Mathematics: 8.g Find the Missing Angle
In this task, 8th graders are presented with a drawing of two parallel lines connected through two line segments. They are given the measures of two angles and are asked to find a third. Aligns with 8.G.A.5.
Texas Instruments
Texas Instruments: Parallel Lines Cut by a Transversal
In this activity, students learn and increase their knowledge about the angles formed when parallel lines are cut by a transversal.
The Math League
The Math League: Corresponding Angles
This tutorial provides a definition of corresponding angles and additional information is provided on angles.
ClassFlow
Class Flow: Angles in Geometry
[Free Registration/Login Required] This flipchart is a look at angles in geometry. Drawing, labeling, measuring, special angles: (right, straight, acute, obtuse) and congruence.
Alabama Learning Exchange
Alex: Build a City on Geometry
The students will be split into small, cooperative groups and build a city following specific guidelines. The students will learn how a city is constructed with angles, intersections, parallel, intersecting, and transversal streets. They...
Sonoma State University
Sonoma State University: Parallel Lines and Similar and Congruent Triangles
This site defines parallel lines, parallel lines cut by a transverse, and congruent triangles. It also contains links for related terms.
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.