Are the two lines parallel perpendicular or neither?
Parallel Lines: If Lines are with the same slope they are parallel.
Perpendicular lines: If the slope of one line is negative reciprocal of the other line, then the lines are perpendicular.
Hence, lines with the same slope are said to parallel lines and if the slope of one line is the negative reciprocal of the other line, then the lines are perpendicular. Else, the lines are said to be just intersecting lines.