Why not see how much you know about this topic already? Then work through the page and see if you can beat your score. Parallel lines are the same distance apart from each other all the way along ...

If lines are perpendicular to each other then \({m_1} \times {m_2} = - 1\) conversely if \({m_1} \times {m_2} = - 1\) then the lines are perpendicular to each other.

Learn how to determine if two vectors are orthogonal, parallel or neither. You can setermine whether two vectors are parallel, orthogonal, or neither uxsing the dot/cross product or using the slope ...