Final answer:
To determine if two lines are parallel or perpendicular, one can use a graphing calculator like Desmos or GeoGebra, where parallel lines have identical slopes and perpendicular lines have negative reciprocal slopes.
Step-by-step explanation:
One online tool that can be used to determine if two lines are parallel or perpendicular is a graphing calculator or software with graphing capabilities, such as Desmos or a geometry software like GeoGebra. To find out if the lines are parallel, you need to compare their slopes. Parallel lines have identical slopes, whereas perpendicular lines have slopes that are negative reciprocals of each other. For example, if one line has a slope of 2, a line perpendicular to it would have a slope of -1/2.
Using a graphing tool, you would plot both lines and examine their slopes. In Microsoft Excel, you can graph two least-squares regression lines and compare the slopes and fit. If using a coordinate system, you would look at the angle vectors A and B make with the x-axis to assess their relationship. The concept of parallelism is based on lines remaining a constant distance apart without intersecting, while perpendicular lines intersect at a 90-degree angle.