Math Planet
Math Planet: Pre Algebra: Angles and Parallel Lines
Explains angles and parallel lines through examples and a video lesson.
Paul Dawkins
Paul's Online Notes: Algebra: Lines
Detailed math tutorial features notes and examples that discuss graphing lines and introduces the concept of slope, the standard form of the line, the point-slope form, slope-intercept form, and parallel and perpendicular lines.
Texas Instruments
Texas Instruments: Angle Sum in Triangles Proof: Rotation and a Parallel Line
This investigation uses Cabri Jr. and a cleaver rotation of a triangle to "prove" that the angles in a triangle add up to 180. This could be used to reinforce triangles and paralled lines as well as introduce the concept of rotating an...
Texas Instruments
Texas Instruments: Getting Started With Ti Navigator: Parallel and Perpendicular
This lesson introduces students to Activity Center and is intended to help students interpret whether lines are parallel or perpendicular. [Requires Adobe Reader.]
University of Regina (Canada)
University of Regina: Math Central: Introduction to Slope for Middle Years Mathematics
This collection of five middle school math lessons covers the topic of plane geometry, specifically the concept of slope. The first lesson introduces middle schoolers to plotting points on a Cartesian grid using a Geoboard. Lesson two...
Math Planet
Math Planet: Pre Algebra: Geometry Fundamental Statements
Provides examples and a video lesson that introduce fundamental statements of geometry.
Oswego City School District
Regents Exam Prep Center: The Basic Locus Theorems
A wealth of resources for teachers introducing locus theorems to students. Lessons cover simple definitions, provide examples and diagrams, and offer connections to real-life situations. Practice exercises offer students online quizzes...
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.
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: 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.
ClassFlow
Class Flow: Segments and Polygons
[Free Registration/Login Required] This flipchart reviews segments, parallel and perpendicular lines and then introduces polygons including quadrilaterals. It has many real world examples of shapes and includes Activote assessment.