Download Section 3.1 Day 1 Lines and Angles

Week 1
10.17.11
Warm Up
1) What is the inverse?
If I run, then you walk.
2) Place marks to show congruence:
AB ≅ EF and DE ≅ BC :
A
C
B
E
D
F
Geometry
3.1 Day 1
I will Identify relationships between lines.
Parallel Lines
When two lines are coplanar and do not intersect.
Skew Lines
When two lines are not coplanar and do not intersect.
Ex 1
Parallel
AB
CD
Skew
EB
CD
Parallel Planes Two planes that do not intersect.
Ex 2
U
W
Planes U and W are Parallel
P 13
Ex 3
Parallel Postulate
If there is a line, and a point not on the line, then
there is exactly one line through the point and
parallel to the other line.
P
Marks
indicate
these lines
are parallel
•
l
P 14
Ex 4
Perpendicular Postulate
If there is a line, and a point not on the line, then
there is exactly one line through the point and
perpendicular to the other line.
•P
l
Transversal A line that intersects two or more coplanar lines.
Ex 5
1 2
3 4
5 6
7 8
Transversal
A line that intersects two or more coplanar lines.
t
Ex 5
corresponding
angles
∠1 and ∠5
1 2
3 4
5 6
7 8
Transversal
A line that intersects two or more coplanar lines.
t
Ex 5
corresponding
angles
alternate
exterior angles
∠1 and ∠5
∠1 and ∠8
1 2
3 4
5 6
7 8
Transversal
A line that intersects two or more coplanar lines.
t
Ex 5
corresponding
angles
∠1 and ∠5
alternate
exterior angles
∠1 and ∠8
alternate
interior angles
∠3 and ∠6
1 2
3 4
5 6
7 8
Transversal
A line that intersects two or more coplanar lines.
t
Ex 5
corresponding
angles
∠1 and ∠5
alternate
exterior angles
∠1 and ∠8
alternate
interior angles
∠3 and ∠6
consecutive
interior angles
∠3 and ∠5
1 2
3 4
5 6
7 8
Review
A _______ is a line that intersects two or more
coplanar lines.
Do: 1
Name the corresponding angles:
Do: 2
Name the alternate interior angles:
2 3
1 4
Assignment:
6 7
5 8
Textbook Page 132, 10 - 26 All
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