Which statement correctly describes parallel lines?

Which statement correctly describes parallel lines?

• A. They lie in the same plane and never intersect
• B. They never intersect
• C. They are non-coplanar
• D. They intersect at a point

Answer: (A)

Parallel lines are two lines that stay in the same plane and never meet. This combination is key: being in one plane ensures they can be compared directly, and never meeting means they keep a constant distance apart. If you only say they never intersect, you’d include lines that aren’t in the same plane (skew lines), which aren’t considered parallel. If you say they are non-coplanar, that describes lines in different planes, which also cannot be parallel. And if they intersect at a point, they obviously aren’t parallel. So the precise description is that parallel lines lie in the same plane and do not intersect.

Parallel lines are two lines that stay in the same plane and never meet. This combination is key: being in one plane ensures they can be compared directly, and never meeting means they keep a constant distance apart.

If you only say they never intersect, you’d include lines that aren’t in the same plane (skew lines), which aren’t considered parallel. If you say they are non-coplanar, that describes lines in different planes, which also cannot be parallel. And if they intersect at a point, they obviously aren’t parallel. So the precise description is that parallel lines lie in the same plane and do not intersect.