1. PARALLEL LINES AND TRANSVERSALS

2. CORRESPONDING ANGLES POSTULATE Two lines cut by a transversal are parallel if and only if the pairs of corresponding angles are congruent.

3. ALTERNATE INTERIOR ANGLES THEOREM Two lines cut by a transversal are parallel if and only if the pairs of alternate interior angles are congruent.

4. ALTERNATE EXTERIOR ANGLES THEOREM Two lines but by a transversal are parallel if and only if the pairs of alternate exterior angles are congruent.

5. CONSECUTIVE INTERIOR ANGLES THEOREM Two lines cut by a transversal are parallel if and only if the pairs of consecutive interior angles are supplementary.

6. CONSECUTIVE EXTERIOR ANGLES THEOREM Two lines cut by a transversal are parallel if and only if the pairs of consecutive exterior angles are supplementary.

7. EXAMPLE Find each numbered angle.

8. EXAMPLE Find the value of x.

9. EXAMPLE Find the value of x. The picture may not be drawn to scale. (3x + 5) o (7x – 15) o

10. TRANSITIVE PROPERTY OF PARALLEL LINES If two lines are parallel to the same line, then they are parallel to each other.

11. ASSIGNMENT Pg. 157 #4-8 all, 27-35 odds Pg. 165 #3-8 all