CK-12 Foundation
Ck 12: Geometry: Lines and Angles Study Guide
This study guide on lines and angles covers key terminology; line notation; parallel, perpendicular, and skew lines; and postulates and theorems about lines. It is available for download with free registration.
Illustrative Mathematics
Illustrative Mathematics: A Rei Solution Sets
For this task, students are shown the graphs of two equations, with areas bounded by their lines and intersections shaded in different colors. They are asked to write a system of equations or inequalities for each shaded area and explain...
Math Planet
Math Planet: Pre Algebra: Geometry Fundamental Statements
Provides examples and a video lesson that introduce fundamental statements of geometry.