Two Lines with Equations
The equations of these 2 lines are in slope-intercept form. The slope and the intercept can be changed with the sliders for each line. Notice what the slopes are when the lines are parallel (never touching). Notice what the slopes are when the lines are perpendicular (at 90 degrees from eachother). This one is harder, but the pattern is easier to see if you convert the slopes into fractions. You can also see if any given point lies on one or both of the lines.