Download Ch. 7-2 Online Notes

Name
Class
Date
Lesson 7-2 Angles and Parallel Lines
Lesson Objective
Common Core State Standard
To identify parallel lines and the angles
formed by parallel lines and transversals
Geometry: 8.G.5
Vocabulary and Key Concepts
When a transversal intersects two parallel lines,
, || m
,
corresponding angles are congruent, and
•
alternate interior angles are congruent.
•
m
All rights reserved.
Transversals and Parallel Lines
t
A transversal is a line that intersects two other lines
at different points
Corresponding angles lie on the same side of the
transversal
and in corresponding positions.
/2 and l7
/3 and l5 /4 and l8
6
7 5 4
1 8
3
© Pearson Education, Inc., publishing as Pearson Prentice Hall.
Examples: /1 and l6 2
a pair of lines and on
Alternate interior angles lie within
opposite sides of the transversal.
Examples: /3 and l6 /4 and l2
Examples
Use this diagram for Examples 1 and 2.
p
q
1 2
5 6
3 4 t
7 8
1 Identifying Angles Identify each pair of corresponding angles and each
pair of alternate interior angles.
/1 and l3 , /2 and l4 , /5 and l7 , /6 and l8 are pairs
of
corresponding angles.
/2 and l7 , /3 and l6 are pairs of alternate interior angles.
64
441198_C3_Ch7_WKbk_Ver-1.indd 64
Course 3 Lesson 7-2
Daily Notetaking Guide
10/10/12 5:46 PM
Name
Class
Date
2 Finding Angle Measures If p is parallel to q, and m/3 5 56°, find m/6
and m/1.
m 6
m 3
m 1
m 3
56°
56°
d
d
Alternate interior
Corresponding
angles are congruent.
angles are congruent.
3 Identifying Parallel Lines In the diagram below, m/5 5 80°, m/6 5 80°, and
m/7 5 80°. Explain why p and q are parallel and why s and t are parallel.
p || q because
All rights reserved.
5
p
6
7
q
t
s
5 and
alternate interior
s || t because
6 and
corresponding
7 are congruent
angles.
7 are congruent
angles.
Quick Check
1. Use the diagram for Examples 1 and 2. Identify each pair of angles as
corresponding, alternate interior, or neither.
a. /3, /6
© Pearson Education, Inc., publishing as Pearson Prentice Hall.
alternate interior
b. /2, /7
corresponding
c. /1, /8
neither
2. In the diagram for Examples 1 and 2, m/3 5 117°. Find m/6 and m/5.
117°, 117°
3. Transversal t is perpendicular to lines  and m. Explain how you know  || m.
t
The right angles are congruent
corresponding angles, so  n m
Daily Notetaking Guide
441198_C3_Ch7_WKbk_Ver-1.indd 65
,
m
Course 3 Lesson 7-2
65
10/10/12 5:46 PM