Download Vocabulary - Hartland High School

Section 3.1 Identify Pairs of Lines & Angles
Goal  Identify angle pairs formed by three intersecting lines.
Lines are PARALLEL if they do not intersect and are coplanar.
Lines are SKEW if they do not intersect and are not coplanar.
Planes are PARALLEL if they do not intersect at all
Example 1: Gives examples for each
Parallel lines
Skew lines
Parallel planes
Example 2: Think of each segment in the figure as part of a line. Which line(s) or plane(s) in
the figure appear to fit the description?
a. Line(s) parallel to AF and containing point E
b. Line(s) skew to AF and containing point E
c. Line(s) perpendicular to AF and containing point E
d. Plane(s) parallel to plane FJI and containing point E
Parallel Postulate (Postulate 13):
If there is a line and a point not on the line,
then there is EXACTLY ONE line through the
point parallel to the given line.
There is exactly one line through P parallel to l
Perpendicular Postulate (Postulate 14):
If there is a line and a point not on the line,
then there is EXACTLY ONE point perpendicular
to the given line.
There is exactly one line through P perpendicular to l
Section 3.1 Identify Pairs of Lines & Angles
Example 3: Use the diagram at the right to answer each question.
a. Name a pair of parallel lines.
b. Name a pair of perpendicular lines.
c. Is AB  BC ? Explain.
Example 4: Identify all pairs of …
a. corresponding angles
b. alternate interior angles
c. alternate exterior angles
d. consecutive interior angles.
Checkpoint: Study each diagram below. And answer questions about them in #1 and 2.
s
a.
a
k
b.
5
n
1
p
c.
3
4
p
6
2
x
y
1. Name the transversal and the lines it cuts.
a.____ cuts _____ & ____
b.____ cuts _____ & _____
b
c. ____ cuts ____ & ____
2. Identify the relationship between the numbered angles in each diagram.
_______________________
_______________________
Classify each pair of numbered angles
3.
4.
____________________
Section 3.1 Identify Pairs of Lines & Angles
Angles Formed by Transversals
t
Transversal
m
A line that intersects two or more coplanar lines at different points
Example:
k
t
Corresponding Angles
m
Two angles that are formed by two lines and a transversal and
occupy corresponding positions.
k
Example:
t
Alternate Interior Angles
m
Two angles that are formed by two lines and a transversal
and lie between the two lines and on opposite sides of the transversal.
k
Example:
t
Alternate Exterior Angles
m
Two angles that are formed by two lines and a transversal and
lie outside the two lines and on opposite sides of the transversal.
Example:
k
t
Consecutive Interior Angles
m
Two angles that are formed by two lines and a transversal and
lie between the two lines and on the same side of the transversal.
k
Example: