Question

How to determine whether the pair of lines is parallel perpendicular or neither?

Answer 1

If the slopes of the 2 lines are equal then they are parallel.

If m1m2 = -1  (where m1 and m2 are the slopes of the 2 lines) then they are perpendicular.

If the 2 slopes do not match either the first or second conditions then they are neither parallel or perpendicular.