1) The document discusses parallel lines and transversals. It defines the corresponding angles postulate, the alternate interior angles theorem, and the alternate exterior angles theorem. 2) These state that if two parallel lines are cut by a transversal, then the corresponding angles are congruent, the alternate interior angles are congruent, and the alternate exterior angles are congruent. 3) It also presents the consecutive interior angles theorem, which states that if two parallel lines are cut by a transversal, then the sum of any pair of consecutive interior angles is 180 degrees.

1. 3.2 Parallel Lines and Transversals September 23, 2011
Bellwork Identify the type of angles.
1. <5, <7 corresponding
4
3 8
7
2. <3, <6 alternate interior 1 2
6
5
3. <1, <8 alternate exterior
11 12
9 10 15 16
4. <15, <16 supplementary 13 14
5. <13. <10 vertical
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 1

2. 3.2 Parallel Lines and Transversals September 23, 2011
3.2 Parallel Lines & Transversals
Postulate 15: Corresponding Angles Postulate
If 2 parallel lines are cut by a transversal,
<2 ≅ <6
then the pairs of corresponding angles are congruent.
2
6
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 2

3. 3.2 Parallel Lines and Transversals September 23, 2011
Theorem 3.1: Alternate Interior Angles Theorem
If 2 parallel lines are cut by a transversal,
<4 ≅ <5
then the pairs of alternate interior angles are congruent.
4
5
Theorem 3.2: Alternate Exterior Angles Theorem
If 2 parallel lines are cut by a transversal,
<1 ≅ <8
then the pairs of alternate exterior angles are congruent.
1
8
Theorem 3.3: Consecutive Interior Angles Theorem
If 2 parallel lines are cut by a transversal,
then the pairs of consecutive interior angles are
<3 + <5 = 180
supplementary
3
5
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 3

4. 3.2 Parallel Lines and Transversals September 23, 2011
With a partner, complete Guided Practice #1 & 2.
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 4

5. 3.2 Parallel Lines and Transversals September 23, 2011
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 5

6. 3.2 Parallel Lines and Transversals September 23, 2011
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 6

7. 3.2 Parallel Lines and Transversals September 23, 2011
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 7

8. 3.2 Parallel Lines and Transversals September 23, 2011
HW pg. 157
#3­19 Odds
23­33 Odds
35 Extra Credit
HW pg. 157 #3­19 odds, 23­33 odds, 35 ec 8