Rossi Parallel and Perpendicular Lines Exploration: What makes them that way?

Students look at lines that are parallel and perpendicular and explain why they think so. They then create their own so they can verify if they were correct or not. There are marble slides at the end of the parallel section, and at the end of the perpendicular section. At the very end there is a card sort for parallel, perpendicular and neither.

By Caro Ross