3.1. Parallel and Skew Lines http://www.ck12.org
3.1 Parallel and Skew Lines
Here you’ll learn about parallel and skew lines.
What if you were given a pair of lines that never intersect and were asked to describe them? What terminology
would you use? After completing this Concept, you will be able to define the terms parallel line, skew line, and
transversal. You’ll also be able to apply the properties associated with parallel lines.
Watch This
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Click image to the left for more content.CK-12 Foundation: Chapter3ParallelandSkewLinesA
Watch the portions of this video dealing with parallel lines.
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Click image to the left for more content.James Sousa:Parallel Lines
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Click image to the left for more content.James Sousa:Parallel Line Postulate
Guidance
Two or more lines areparallelwhen they lie in the same plane and never intersect. The symbol for parallel is||. To
mark lines parallel, draw arrows(>)on each parallel line. If there are more than one pair of parallel lines, use two
arrows(>>)for the second pair. The two lines below would be labeled
←→
AB||
←→
MNorl||m.For a line and a point not on the line, there is exactly one line parallel to this line through the point. There are
infinitely many lines that pass throughA, but only one is parallel tol.