Two parallel lines, a plane and a line in a plane parallel to it.
They can be, but not necessarily. If two lines in the same plane never intersect, they are parallel. Though, two lines can exist in the same plane without being parallel. Ie, two lines that intersect at a 90 degree angle are perpendicular. Most lines in a plane aren't parallel.
Parallel lines
Two lines are coplanar iff they are parallel OR intersect.
parallel lines :)
They are parallel lines
Two parallel lines, a plane and a line in a plane parallel to it.
Two lines that do not intersect on the same plane are Parallel lines.
They can be, but not necessarily. If two lines in the same plane never intersect, they are parallel. Though, two lines can exist in the same plane without being parallel. Ie, two lines that intersect at a 90 degree angle are perpendicular. Most lines in a plane aren't parallel.
Parallel lines
If the two lines lie in the same plane, and they do not intersect, then they are parallel. If they are not in the same plane, and do not intersect, then they are called skew lines.
Parallel lines.
Two lines are coplanar iff they are parallel OR intersect.
parallel lines :)
They are parallel lines
Because they are parallel lines.
Pretty much the only thing you need to know to determine if two lines are parallel is the gradient of those lines. Simply put, are the lines on the same plane?