Use models (such as dynamic geometry software, patty paper and geo boards) to explore relationships among angles (complementary, supplementary, interior, exterior, vertical, and corresponding).0806.1.6

Links verified on 08/17/2026

1. Complementary & Supplementary Angles - Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles.
2. Creating Congruent Triangles - materials needed: rulers and protractors [This expired page is brought to you by the Internet archive, the Wayback Machine.]
3. GeoGebra Geometry - use to draw intersecting lines and polygons.
4. GeoGebra Tutorial -(VIDEO) An introduction and how to use GeoGebra for beginners.
5. Math Playground - a small but growing collection of manipulatives for teaching and learning or
6. Measuring Angles - Practice lining up and reading a protractor while you measure a set of angles in a fun learning activity or
7. National Library of Virtual Manipulatives Home - select topic and grade level to find appropriate manipulatives or
8. Tangrams - interactive geometry site or
9. Vertical Angles Explained - explanation and examples in this video
10. Wolfram Demonstrations Project - a free resource of interactive visualizations from elementary education to the frontiers of research