Few weeks ago in math10 we learned how to determine if the lines are parallel or perdicular or neither of them.

If they have the same slope, the lines are parallel and if the product of slopes is negative one then the lines are perpendicular.

e.g) m1 = 1/4    m2 = 3/12 – this is parallel because they have the same slope.

m1 = 9/3     m2 = -1/3 – this is perpendicular because the product of these two fractions is – 1.