Warm - Up Go over any problems that you got wrong on the test with your seat partner

Parallel Lines and Planes Chapter 3

Definitions Parallel lines –Algebra 1 review: two lines that have the same slope –Geometry application: two coplanar lines that do not intersect

If the are not parallel… Two other options –Intersecting –Skew Definition: lines that are not coplanar Note: skew lines are neither parallel nor intersecting.

Can you find an example of skew lines in the classroom?

Parallel Planes Definition: planes that do not intersect –Such as… Note: all planes are either parallel or intersecting

Sometimes, Always, Never 1.Two lines in the same plane are ____ parallel. 2.Two lines in the same plane are __ skew. 3.Two noncoplanar lines ____ intersect. 4.Two planes ____ intersect. 5.If two planes do not intersect, then they are ______ parallel.

Answers 1.Two lines in the same plane are S parallel. 2.Two lines in the same plane are N skew. 3.Two noncoplanar lines N intersect. 4.Two planes S intersect. 5.If two planes do not intersect, then they are A parallel.

Theorem– Parallel lines of intersection. If 2 parallel planes are cut by a third plane, then the lines of intersection are parallel. Show me examples in the classroom!

Transversal A line that intersects lines in different points.

Practice!! Do #1-6 of the practice alone!! True or False Name the Transversal

Describing Angles Exterior angles Interior angles Alternate interior angles Alternate exterior angles Same-side interior angles Same-side exterior angles Corresponding angles

Practice!! What angles are formed when two lines are cut by a transversal?

With Your Partner Name the 2 lines and the transversal that form each pair of angles.

More Practice! Do classroom exercises on pg 75 with a group of 3 or 4.

Homework Mini-Quiz on 3.1 Tomorrow Pg #1-17, ODD