Perpendicular straight lines
From Encyclopedia of Mathematics
Straight lines forming a right angle with each other (such straight lines need not intersect in space). A straight line 
and a plane 
are said to be mutually perpendicular if 
is perpendicular to any straight line lying in 
. See Orthogonality for a generalization of the concept of perpendicularity.
How to Cite This Entry:
Perpendicular straight lines. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Perpendicular_straight_lines&oldid=16479
Perpendicular straight lines. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Perpendicular_straight_lines&oldid=16479