3.1 Parallel Lines and Transversals
Glencoe Geometry Interactive Chalkboard
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Objectives

Identify the relationships between two lines
or two planes

Name angles formed by a pair of lines and
a transversal
Relationships Between Lines

Parallel Lines – lines that are coplanar and
do not intersect; We use the symbol || to
represent parallel lines, (i.e. AB || CD).

Skew Lines – lines that do not intersect
and are not coplanar

Parallel Planes – two planes that do not
intersect
Example 1a:
Name all planes that are parallel to plane AEF.
Answer: plane BHG
Example 1b:
Name all segments that intersect
Answer:
Example 1c:
Name all segments that are parallel to
Answer:
Example 1d:
Name all segments that are skew to
Answer:
Your Turn:
Use the figure to name
each of the following.
a. Name all planes that are parallel to plane RST.
Answer: plane XYZ
b.
Answer:
c.
Answer:
d.
Answer:
Relationships Between Lines
and the Angles Formed
 Transversal
- a line that intersects two
or more coplanar lines at different points
1 2
3 4
5 6
7 8

Angles 1 and 5 are
corresponding angles

Angles 1 and 8 are
alternate exterior
angles
Relationships Between Lines
and the Angles Formed

1 2
3 4
5 6
7 8

Angles 3 and 6 are
alternate interior
angles.
Angles 3 and 5 are
consecutive interior
angles or same side
interior angles
Example 2a:
BUS STATION Some of a bus station’s driveways
are shown. Identify the sets of lines to which line v
is a transversal.
Answer: w and u, w and x, w and z, u and z
Example 2b:
BUS STATION Some of a bus station’s driveways
are shown. Identify the sets of lines to which line y is
a transversal.
Answer: w and u, w and x, w and z, u and z
Example 2c:
BUS STATION Some of a bus station’s driveways
are shown. Identify the sets of lines to which line u
is a transversal.
Answer: v and y, y and x, v and z, y and z
Example 2d:
BUS STATION Some of a bus station’s driveways
are shown. Identify the sets of lines to which line w
is a transversal.
Answer: v and y, y and x, v and z, y and z
Your Turn:
HIKING A group of nature trails is shown. Identify the
sets of lines to which each given line is a transversal.
a. line a
Answer: lines c, d, e, f
b. line b
Answer: lines c, d, e, f
c. line c
Answer: lines a, b, d, e, f
d. line d
Answer: lines a, b, c, e, f
Example 3a:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: corresponding
Example 3b:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: alternate exterior
Example 3c:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: corresponding
Example 3d:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: alternate exterior
Example 3e:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: alternate interior
Example 3f:
Identify
as alternate interior, alternate
exterior, corresponding, or consecutive interior
angles.
Answer: consecutive interior
Your Turn:
Identify each pair of angles as alternate interior,
alternate exterior, corresponding, or consecutive
interior angles.
a.
Answer: consecutive interior
b.
Answer: corresponding
c.
Answer: alternate exterior
Your Turn:
Identify each pair of angles as alternate interior,
alternate exterior, corresponding, or consecutive
interior angles.
d.
Answer: alternate interior
e.
Answer: corresponding
f.
Answer: alternate exterior
Assignment

Geometry:
Pg. 128 – 130 #2 – 48 evens

Pre-AP Geometry:
Pg. 128 – 130 #2 – 48 evens, #58