Transcript 3.1 Lines & Angles

1/13
SECTIONS 3.1 & 3.3
TRANSVERSALS & ANGLES
2/13
PARALLEL LINES
What do you know about parallel lines?
How would you define parallel lines?
A
B
D
C
H
E
G
F
3/13
SKEW LINES
Parallel lines (ll) – coplanar lines that do not intersect
l ll m
l
m
Skew lines – non-coplanar lines that do not intersect.
A
Parallel Planes – Two planes
that never intersect.
B
D
C
H
E
G
F
PRACTICE
1. Line AB & Line DC are ____________
2. Line AB & Line EF are ____________
3. Line BC & Line AH are ____________
4. Plane ABC & Plane HGF are _________
5. Line AC & Line HG are ___________
A
B
D
C
H
E
A) Parallel
G
F
B) Skew
4/13
INTERSECTING LINES
5/13
When two lines intersect a number of angle types are
formed, Vertical Angles & Linear Pairs.
t
m
1
2
4
3
PERPENDICULAR LINES
Perpendicular Lines - Coplanar lines that
intersect to form four right angles. (Symbol )
m

h
m
h
6/13
TRANSVERSAL
A transversal is a line, ray or segment that
intersects two or more coplanar lines.
t
m
g
7/13
ANGLES FORMED BY A TRANSVERSAL
t
m
1
2
4
3
INTERIOR
INTERIOR
g
5
6
8
CORRESPONDING ANGLES
ALTERNATE INTERIOR
ALTERNATE EXTERIOR
CONSECUTIVE INTERIOR (SAME SIDE INTERIOR)
CONSECUTIVE EXTERIOR (SAME SIDE EXTERIOR)
7
8/13
ANGLES FORMED BY A TRANSVERSAL & PARALLEL LINES
t
9/13
m
1
m
||
g
INTERIOR
g
2
4
3
5
INTERIOR
6
8
7
CORRESPONDING ANGLES
1  5, 2  6, 3  7, 4  8
ALTERNATE INTERIOR
4 & 6, 3 & 5
ALTERNATE EXTERIOR
1 & 7, 2 & 8
CONSECUTIVE INTERIOR (SS INTERIOR)
4 & 5, 3 & 6
CONSECUTIVE EXTERIOR (SS EXTERIOR)
1 & 8, 2 & 7
10/13
PRACTICE
m
t
m
||
g
1
2
4 3
9
10
11 12
14
13
15
16
g
m4 = 125
m14 = 85
5
6
7
h
8
PRACTICE
11/13
t
m
m
||
g
g
 2 x  17  
65
PRACTICE
In the diagram below,
intersected by
PF and MH are parallel lines
EK. What is the measure of GJH ?
12/13
HOMEWORK 3.1 & 3.3
P. 132
6 – 17
P. 146
8 – 26
13/13