| M5 Home Page |
| About.com | Geometry: An Introduction (Terms) |
| Ask Dr. Math | Ray, Line Segment Line |
| Everyday Math | Points and Line Segments |
| Everyday Math | Points, Line Segments, Rays, and Lines |
| Math League | Basic Terms |
| Math Reference | Plane Geometry, Points and Lines |
| NCTM Illuminations | Interactive Geometry Dictionary: Lines in Geometry |
| Pink Monkey | Basic Concepts in Geometry |
| Shodor | Lines, Rays, Line Segments, and Planes |
| Delphi for Fun | Intersecting Lines |
| Interactive Mathematics | Parallel Lines |
| Math to Build On | Crossing and Parallel Lines |
| SparkNotes | Parallel Lines |
| SparkNotes | Perpendicular Lines |
| SparkNotes | Dividing Angles and Segments |
| A+ Math | Geometry Flashcards |
| A+ Math | MATHO Geometry Game |
| A+ Math | Geometry Hidden Picture Game |
| Kids Newsroom | Lines, Rays, and Angles Quiz |
| SparkNotes | Dividing Angles and Segments - Practice |
| SparkNotes | Parallel Lines - Problems |
| SparkNotes | Perpendicular Lines - Problems |
| EdHelper | Lines and Line Segments (1) |
| EdHelper | Lines and Line Segments (2) |