Math Planet
Math Planet: Pre Algebra: Angles and Parallel Lines
Explains angles and parallel lines through examples and a video lesson.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Line and Angle Relationships
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of line and angle relationships.
Mr. Martini's Classroom
Mr. Martini's Classroom: Geometry Special Angle Pairs and Parallel Transversals
Students are challenged to identify and measure angles created by parallel lines and a transversal as well as complementary and supplementary pairs.
University of Georgia
University of Georgia: Inter Math: Exterior Angles
Intermath Dictionary's site defines terms relating to angles, gives examples, and offers interactive exercises.