1. Angles and Parallel Lines1 2 3 4 5 6 7 8

2. Corresponding Angle Postulate
If two parallel lines are crossed by a transversal, then each pair of corresponding angles are congruent. 1 2 3 4 5 6 7 8

3. Alternate Interior Angles Theorem
If two parallel lines are crossed by a transversal, then each pair of alternate interior angles are congruent. 1 2 3 4 5 6 7 8

4. Consecutive Interior Angles Theorem
If two parallel lines are crossed by a transversal, then each pair of consecutive interior angles are supplementary. 1 2 3 4 5 6 7 8

5. Alternate Exterior Angles Theorem
If two parallel lines are crossed by a transversal, then each pair of alternate exterior angles are congruent. 1 2 3 4 5 6 7 8

6. Perpendicular Transversal Theorem
In a plane, if a line is perpendicular to one of two parallel lines, then it is perpendicular to the other. a b c

7. Angles and Parallel Lines
Make a sketch of the problem in your notes.
Angles and Parallel Lines
Given j || k,
Applications –
Find the measure of 3 4 5 2 1.
43o 1 7 8 6 9
Corresponds with 1. 11 10 2.
24o 12
Alternate exterior with 13 3.
156o
Linear pair with o – 24o = 156o 14

8. Angles and Parallel Lines
Given j || k,
Find the measure of
Applications – 3 4 5 2 4.
137o 1 7 8 6 9
Linear pair with 3. 11 10 5.
156o 12
Vertical angle with 13 6.
43o
Vertical with Alternate Interior of 3. 14