- Thomas Walton
Parallel: I noticed the slopes of the parallel lines were always the same. I used the algebra feature and changed the form of the line to slope-intercept in order to confirm this. Perpendicular: Going into this I already knew that the slopes of perpendicular lines were opposite reciprocals, but geogebra did not make this obvious. The only thing I could observe from geogbra is that if one line had a positive slope, then the other had a negative slope. (unless they formed a perfect 90 degree angle) This was because geogebra did not put the slopes in fraction form.