you can find the slope of the two lines...when it is perpendicular
m1*m2=-1
m1=one of the slope
m2=the second slope
if you multiply the slopes together, you will get -1 if it is perpendicular.
How can you determine if two lines are perpendicular?
2 answers
Multiply the slope of one by the slope of the other. If the product is -1, they are perpendicular.