1. Parallel Lines and Angles
Corresponding Angles Postulate
If two parallel lines are cut by a transversal, then each pair of corresponding angles is congruent.
Alternate Interior Angles Theorem
If two parallel lines are cut by a transversal, then each pair of alternate interior angles is congruent.

2. Angles and Parallel Lines
Consecutive Interior Angles Theorem
If two parallel lines are cut by a transversal, then each pair of interior angles on the same side of the transversal is supplementary.
Alternate Exterior Angles Theorem
If two parallel lines are cut by a transversal, then each pair of alternate exterior angles is congruent.
Perpendicular Transversal Theorem
If a transversal intersecting two parallel lines is perpendicular to one of the lines, it is perpendicular to the other line.

3. In the figure and Find
Answer:
Example 2-1b

4. Grid-In Test Item What is the measure of IGE? Answer:
Example 2-2d

5. ALGEBRA If
and
find x and y.
Answer:
Example 2-3h