How do you determine if a line is perpendicular, parallel, or neither? Algebra Forms of Linear Equations Equations of Perpendicular Lines 1 Answer 1s2s2p Apr 18, 2018 Say we have the two lines: "Line 1":y=m_1x+c_1 "Line 2":y=m_2x+c_2 If m_1=m_2 then the lines are parallel, since they both have the same rate of change and therefore will never cross. If m_1m_2=-1 then they are perpendicular. Answer link Related questions How do you determine the equation of a line that is perpendicular to another? What is the relationship between equations of perpendicular lines? How do you find the equation of the line perpendicular to the line y=5 and passing through (5, 4)? What is the slope that is perpendicular to 2x+8y=9? How do you determine if the two lines are parallel, perpendicular, or neither if line a passes... How do you find the equation of a line that is perpendicular to y=2/3x-4 and goes through point (6,-2)? How do you determine if 5y+3x=1 is parallel, perpendicular to neither to the line y+10x=-3? Question #3177e How do you find the equation of the line through the point (-4 , 5) and is perpendicular to the x axis? How do you find the equation of the line through the point (6 , -1) and is perpendicular to the y axis? See all questions in Equations of Perpendicular Lines Impact of this question 10467 views around the world You can reuse this answer Creative Commons License