Group students and have them split up the cards. They should first find the slope of each equation or line and fill in the slopes in the table at the top of the page. Then the groups will discuss which lines are parallel, perpendicular, or neither and group the cards accordingly. The lines on the cards are in slope-intercept form, standard form, and graphed. There is an answer key included! This is a great activity to encourage group work, communication, and collaboration.