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2 answers:
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Answer:
1. always
2. sometimes
Step-by-step explanation:
Two lines are coplanar if they lie in the same plane or in parallel planes. There is ALWAYS a plane which contains two parallel lines (see first attached image for details).
Two lines that lie in parallel planes are sometimes parallel. For example, see at second image. Planes and
are parallel. Consider pair of lines
and
- they are parallel, but if you consider the pair of lines
and
, you can see they are not parallel.
