1-1a Slide 1 of 1 (over Chapter 3)

1-1b Slide 1 of 1 (over Chapter 3)

 § 4.1 Parallel Lines and Planes Parallel Lines and PlanesParallel Lines and Planes  § 4.4 Proving Lines Parallel Proving Lines ParallelProving Lines Parallel  § 4.3 Transversals and Corresponding Angles Transversals and Corresponding AnglesTransversals and Corresponding Angles  § 4.2 Parallel Lines and Transversals Parallel Lines and TransversalsParallel Lines and Transversals  § 4.6 Equations of Lines Equations of LinesEquations of Lines  § 4.5 Slope Slope

You will learn to describe relationships among lines, parts of lines, and planes. In geometry, two lines in a plane that are always the same distance apart are ____________. parallel lines No two parallel lines intersect, no matter how far you extend them.

Definition of Parallel Lines Two lines are parallel iff they are in the same plane and do not ________. intersect

Planes can also be parallel. The shelves of a bookcase are examples of parts of planes. The shelves are the same distance apart at all points, and do not appear to intersect. They are _______. parallel In geometry, planes that do not intersect are called _____________. parallel planes Q J K M L S R P Plane PSR || plane JML Plane JPQ || plane MLR Plane PJM || plane QRL

Sometimes lines that do not intersect are not in the same plane. These lines are called __________. skew lines Definition of Skew Lines Two lines that are not in the same plane are skew iff they do not intersect.

A C B E G H D F Name the parts of the figure: 1) All planes parallel to plane ABF 2) All segments that intersect 3) All segments parallel to 4) All segments skew to Plane DCG AD, CD, GH, AH, EH AB, GH, EF DH, CG, FG, EH