® Direction ratios of a line are the numbers which are proportional to the

® Direction ratios of a line are the numbers which are proportional to the direction cosines of a line. ® If l , m , n are the direction cosines and a , b , c are the direction ratios of a line then l = ; m = ; n = ® Skew lines are lines in space which are neither parallel nor intersecting. They lie in different planes.