How do you use the slope to prove lines are parallel or perpendicular

In order to find if two lines are parallel or perpendicular or neither, following rules are used:

If the slope of two lines is the same, the two lines will be parallelIf the product of slopes of two lines is -1, the two lines will be perpendicular to each other.If none of the above two conditions is being satisfied, this mean lines are neither parallel nor perpendicular.

So the steps that must be followed are:

Find the slope of the given lines.Use the values of the slope to check which of the above point is being satisfied and draw the conclusion accordingly.