In the xy plane, line k passes through the point (1,1) and line m passes thru point (1,-1). Are lines k and m perpendicular to each other?


1. Lines k and m intersect at point (1,-1)
2. Line k intersects at the x axis at point (1,0).





Answer is E.


Does a perpendicular mean that the lines have to form to be 90 degrees? If so then I can take it from here....