parallel, transversal, geometry, theorem, exterior angles, interior, corresponding, alternate

1. 3.2 Use Parallel lines and3.2 Use Parallel lines and
TransversalsTransversals
Mr. Saucedo
Geometry
Milby High School

2. OBJECTIVE:OBJECTIVE:
We will pair angle theorems to find
measurements of angles.

3. ACTIVITYACTIVITY
Materials:
◦ Activity worksheet
◦ Protractor
Step 1: Measure all the angles created by the
transverals in the pictures.
Step 2: Look for patterns.
Step 3: Explain your patterns.

4. POSTULATE 15:POSTULATE 15:
CORRESPONDING ANGLESCORRESPONDING ANGLES
If two parallel lines are cut by a
transversal, then the pairs of
corresponding angles are congruent.

5. THEOREM 3.1:THEOREM 3.1:
Alternate Interior Angles TheoremAlternate Interior Angles Theorem
If two parallel lines are cut by a
transversal, then the pairs of alternate
interior angles are congruent.
<1 ≈ <2
m<1 = m<2

6. THEOREM 3.2:THEOREM 3.2:
Alternate Exterior Angles TheoremAlternate Exterior Angles Theorem
If two parallel lines are cut by a
transversal, then the pairs of alternate
exterior angles are congruent.
<1 ≈ <8
m<1 = m<2

7. THEOREM 3.3:THEOREM 3.3:
Consecutive Interior AnglesConsecutive Interior Angles
TheoremTheoremIf two parallel lines are cut by a
transversal, then the pairs of consecutive
interior angles are supplementary.
m<3 + m<5 = 180
or
m<4 + m<6 = 180

8. CHECKPOINTCHECKPOINT
TRUE OR FALSE?
1. Angles A and H are congruent.
2. Angles C and E add up to 180 degrees.
3. Angles D and F add up to 180 degrees.
4. Angles B and G are congruent.
5. Angles A and G add up to 180 degrees.
6. Angles D and E add up to 180 degrees.
7. Angles D and F are supplementary.

9. CHECKPOINTCHECKPOINT
True or False?
1.Angles 4 and 6 are congruent.
2.Angles 2 and 5 are congruent.
3.Angles 7 and 1 add up to 180 degrees.
4.Angles 3 and 8 are congruent.
5.Angles 8 and 2 add up to 180 degrees.

10. GUIDEDGUIDED
PROBLEMPROBLEM
If m<1 = 30, find the
Measurement of all the
Other angles.
1 = 5=
2= 6=
3= 7=
4= 8=

11. GUIDED PROBLEMGUIDED PROBLEM
m<f = 115 and
m<c = x + 5,
Find x.

12. CHECKPOINTCHECKPOINT
m<d = 135 and
m<f = x – 30.
Find x.

13. INDEPENDENT PRACTICEINDEPENDENT PRACTICE
BIG BOOK: PAGE 157
PROBLEMS:
1, 4, 5, 6, 7, 8, 10, 12, 14, 18, 22, 33.
PRE-AP: ADD PROBLEM 28.

14. HOMEWORK:HOMEWORK:
SECTION 3.2
WORKBOOK, PAGE 46 & 47
PROBLEMS: 1-20 all problems.