CK-12 Foundation
Ck 12: Interactive Geometry: 5.2 Bisectors of Line Segments and Angles
Learn how to construct bisectors of line segments and angles.
Math Planet
Math Planet: Geometry: Measure and Classify an Angle
Explains the terms and symbols used to discuss line angles, what an angle is, and the types of angles. Includes short video lesson demonstrating how to use a protractor to measure an angle. [0:57]
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?
Sonoma State University
Sonoma State University: Parallel Lines and Similar and Congruent Triangles
This site defines eleven theorems relating to parallel lines and similar and congruent triangles. Links to the theorems and relevant term descriptions are provided.
Other
800score: Intersecting Angles
Read a description of intersecting lines and all about the different kinds of angles they form. Includes examples.
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.
Oswego City School District
Regents Exam Prep Center: Geometry Vocabulary Resources
A list of geometry definitions and a matching activity.
CK-12 Foundation
Ck 12: Geometry: Midpoints and Segment Bisectors
[Free Registration/Login may be required to access all resource tools.] Apply the definitions of midpoint, segment bisector, and angle bisector.
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.
CK-12 Foundation
Ck 12: Interactive Geometry: 5.1 Copies of Line Segments and Angles
Construct a copy of a line segment in this interactive exercise.
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.
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.
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.
Math Planet
Math Planet: An Introduction to Geometry
Provides an introduction to geometry with definitions of points, lines, planes and angles through the use of examples and a brief video lesson. [1:28]
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.
Oswego City School District
Regents Exam Prep Center: Copy a Line Segment and an Angle
This site provides a step-by-step method to construct congruent segments and angles with a straight edge and compass.
Oswego City School District
Regents Exam Prep Center: Theorems and Postulates for Geometry
Here is a partial list of theorems, postulates, and properties.
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.
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.
Cuemath
Cuemath: Angles
A comprehensive guide for learning all about angles with definitions, examples, and practice questions.
CK-12 Foundation
Ck 12: Geometry: Vertical Angles Grade 7
[Free Registration/Login may be required to access all resource tools.] Identify adjacent and vertical angles formed by intersecting lines and then find missing angle measures.
CK-12 Foundation
Ck 12: Geometry: Vertical Angles
[Free Registration/Login may be required to access all resource tools.] Identify adjacent and vertical angles formed by intersecting lines and then find missing angle measures.