<P> In geometry , parallel lines are lines in a plane which do not meet ; that is , two lines in a plane that do not intersect or touch each other at any point are said to be parallel . By extension , a line and a plane , or two planes , in three - dimensional Euclidean space that do not share a point are said to be parallel . However , two lines in three - dimensional space which do not meet must be in a common plane to be considered parallel ; otherwise they are called skew lines . Parallel planes are planes in the same three - dimensional space that never meet . </P>
<P> In geometry , parallel lines are lines in a plane which do not meet ; that is , two lines in a plane that do not intersect or touch each other at any point are said to be parallel . By extension , a line and a plane , or two planes , in three - dimensional Euclidean space that do not share a point are said to be parallel . However , two lines in three - dimensional space which do not meet must be in a common plane to be considered parallel ; otherwise they are called skew lines . Parallel planes are planes in the same three - dimensional space that never meet . </P>
two lines in the same plane that do not intersect are called
two lines in the same plane that do not intersect are called
parallel lines
parallel lines