Download Chapter 7 Reasoning and Parallel Lines

Chapter 7
Reasoning and Parallel Lines
7­1 Parallel Lines and Related Angles
Objective: Indentify pairs of angles formed by two lines and a transversal; relate the measures of angles formed by parallel lines and a transversal.
WARM UP
1 2
3 4
Name a pair of vertical angles.
5 6
7 8
Name a pair of adjacent angles.
transversal -- a line that intersects two coplanar lines
at two distinct points.
t
** line t is a transversal
m
2
1
4
3
** 8 angles are formed by a 5
6
transversal and the 2 lines
7
8
n
Special Pairs of Angles
Corresponding Angles --
a pair of angles that are
in the same relative
position in relation to
each line and the
transversal
t
m
2
1
4
3
5
6
7
8
n
Special Pairs of Angles
t
Alternate Interior Angles --
a pair of angles that are in
the interior of the 2 lines and
on alternate sides of the
transversal
m
2
1
3
4
n
Special Pairs of Angles
t
Same-Side Interior Angles -a pair of angles that are in the
interior of the 2 lines and on
the same-side of the
transversal
2
1
3
m
4
n
Special Pairs of Angles
t
Alternate Exterior Angles -1
a pair of angles that are in
the exterior of the 2 lines
and on alternaate sides of
the transversal
2
3
4
Give an example of each angle pair.
2
4
6
8
a) Corresponding
b) Alternate Interior
c) Alternate Exterior
d) Same Side Interior
5
7
3
1
*** If the 2 lines are parallel,
what is your conjecture about ...
1
2
3 4
6
5
8
7
corresponding angles??
alternate interior angles??
*** If the 2 lines are parallel,
1
2
3 4
6
5
8
7
what is your conjecture about ...
same-side interior angles??
alternate exterior angles??
7-1
What is the value of x?
n ll m
n
m
40o
x
Given: a ll b
Conclusion
Reason
t
1
2
3
a
4
5
6
7
8
b
HW #79:
Page 366­67
1 ­ 13,18 ­ 27
(Note: # 4­7 just find m<1 & m<2)