## Objectives

• SWBAT recognize and notate perpendicular lines, and use properties thereof
• SWBAT recognize and notate parallel lines, and use properties thereof

## PA Standards

• PA 2.3.8.C. Measure angles in degrees and determine relations of angles.
• PA 2.5.11.B. Use symbols, mathematical terminology, standard notation, mathematical rules, graphing and other types of mathematical representations to communicate observations, predictions, concepts, procedures, generalizations, ideas and results.
• PA 2.9.5.A. Give formal definitions of geometric figures.
• PA 2.9.5.L. Identify properties of geometric figures (e.g., parallel, perpendicular, similar, congruent, symmetrical).
• PA 2.9.8.B. Draw, label, measure and list the properties of complementary, supplementary and vertical angles.

## Introduction to New Material

Define perpendicular lines (what they are, how to notate it on a diagram, and the notation in a statement).

Define a transversal (any line which cuts across a set of lines) but note that it's usually talked about only in terms of parallel lines. Describe what they are, how to notate them on a diagram, and how to notate it in a statement.

Given a pair of lines cut by a transversal, define the corresponding angles, the alternate interior angles, and the alternate exterior angles.

Note that when parallel lines are cut by transversals, the corresponding angles are congruent. (Add linear pairs and vertical angles and you know everything from one angle.)

Same for alternate interior angles and alternate exterior angles.

## Classwork

Students should do the problems on pages 31, 32, and 33.