Section 3-2: Proving Lines Parallel Goal 2.02 Apply properties, definitions, and theorems of angles and lines to solve problems and write proofs.
Essential Questions 1. What are the angle conditions that produce parallel lines? 2. How are distance relationships among points, lines, and planes recognized and used?
Postulate for 3-2 If two lines are cut by a transversal and corresponding angles are congruent, then the lines are parallel.
Theorems for If two lines are cut by a transversal and alternate interior angles are congruent, then the lines are parallel. 21. If two lines are cut by a transversal and same-side interior angles are supplementary, then the lines are parallel.
In a plane, two lines perpendicular to the same line are parallel. Two lines parallel to a third line are parallel to each other.
distance between a point and a line or plane the length of the segment perpendicular to the line or plane from the point
Examples p Together: even
Examples p Students: p 126: 18 – 22 even p 127: 27 – 30
Homework Textbook p 129: Mixed Review, 56 – 62 all Practice 3-2