Texas Instruments
Texas Instruments: Parallel or Perpendicular What's Your Inclination?
This activity has students discover the relationship between parallel and perpendicular lines and their slopes. After constructing these objects using CABRI Geometry II for the TI-89, slopes are measured. [Requires Adobe Reader.]
Texas Instruments
Texas Instruments: Parallel and Perpendicular Slopes
This activity is for use as a formative assessment tool after the introduction and overview of parallel and perpendicular slopes.