Download 3.2 Notes

Geometry
Opportunity is
missed by most
people because it is
dressed in overalls
and looks like work.
Thomas Edison
Today:
•Homework Check
•3.2 Check Up
•Practice
Yesterday
Opportunity is
missed by most
people because it is
dressed in overalls
and looks like work.
Thomas Edison
Assignment:
• 3.1-3.2 p. 197 #1-14
3.2
3.1 Check Up
Identify the vocabulary term for each pair
of angles represented in the picture.
1. 3 and 6
2. 1 and 8
3. 2 and 6
4. 1 and 6
5. 3 and 5
You named angle pairs formed by parallel lines
and transversals.
• Use theorems to determine the relationships
between specific pairs of angles.
• Use algebra to find angle measurements.
Content Standards
G.CO.1 Know precise definitions of angle, circle,
perpendicular line, parallel line, and line segment,
based on the undefined notions of point, line, distance
along a line, and distance around a circular arc.
G.CO.9 Prove theorems about lines and angles.
Mathematical Practices
1 Make sense of problems and persevere in solving
them.
3 Construct viable arguments and critique the
reasoning of others.
3.2 Angles and Parallel Lines
Objectives:
1. Properties of parallel lines and
transversals
2. Using properties of parallel lines
in proofs
Vocabulary:
parallel, transversal, corresponding,
alternate interior, alternate exterior,
consecutive interior
3.2 Angles and Parallel Lines
If 2 parallel lines are cut by a transversal, then:
corresponding angles are congruent.
alternate interior angles are congruent.
alternate exterior angles are congruent.
consecutive interior angles are supplementary.
1 2
4 3
5 6
8 7
3.3 Parallel Lines and Transversals
If l1|| l2 , find x.
What type of
angles do you
have?
Alternate
Exterior
x = 53
l1
2x + 4
l2
110
If l1|| l2 , find x and y.
x = 105
y = 85
y + 20
x
75
l1
l2
3.3 Parallel Lines and Transversals
How many angles in the diagram
have a measure of 100o?
100o
Given: l1 || l2
l3 || l4
Prove: 1   2
Statements
2
3
1
Reasons
1. Given  ALWAYS
4. Transitive Property of
Congruency.
Geometry
Opportunity is
missed by most
people because it is
dressed in overalls
and looks like work.
Thomas Edison
Assignment:
•
3.2 p. 183 #5, 8, 25, 49