Rays and angles and Star Wars? It sounds strange, but it's actually a fun game to help fourth graders get good at measuring and identifying angles and rays with a protractor. Each pair of children chooses which Star Wars character they'd...

A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...

You can pick up some valuable pointers on angles and lines here. When you finish working your way through the pages you can take an on-line "Test Bite," and check your understanding.