Lesson 4-2Parallel Lines and Transversals

Ohio Content Standards:

Ohio Content Standards:

Recognize and apply angle relationships in situations

involving intersecting lines, perpendicular lines and

parallel lines.

Ohio Content Standards:

Recognize the angles formed and the relationship between

the angles when two lines intersect and when parallel

lines are cut by a transversal.

Transversal

TransversalA line that intersects

two or more lines, each at different points.

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

Interior Angles

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

Exterior Angles

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

Alternate Interior Angles

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

Alternate Exterior Angles

TransversalA line that intersects

two or more lines, each at different points.

b

c

r

1 234

5 6

78

Consecutive Interior Angles

Identify each pair of angles as Identify each pair of angles as alternate alternate interior, alternate exterior, consecutive interior, alternate exterior, consecutive

interior, interior, or or vertical.vertical.

Identify each pair of angles as Identify each pair of angles as alternate alternate interior, alternate exterior, consecutive interior, alternate exterior, consecutive

interior, interior, or or vertical.vertical.

1 23 4

5 6

7 8

Identify each pair of angles as Identify each pair of angles as alternate alternate interior, alternate exterior, consecutive interior, alternate exterior, consecutive

interior, interior, or or vertical.vertical.

1 23 4

5 6

7 8

5 and 3

Identify each pair of angles as Identify each pair of angles as alternate alternate interior, alternate exterior, consecutive interior, alternate exterior, consecutive

interior, interior, or or vertical.vertical.

1 23 4

5 6

7 8

8 and 1

Theorem 4-1Alternate Interior

Angles

Theorem 4-1Alternate Interior

AnglesIf two parallel

lines are cut by a transversal, then each pair

of alternate interior angles is congruent.

Theorem 4-1Alternate Interior

AnglesIf two parallel

lines are cut by a transversal, then each pair

of alternate interior angles is congruent.

34

5 6

Theorem 4-2Consecutive Interior

Angles

Theorem 4-2Consecutive Interior

AnglesIf two parallel

lines are cut by a transversal, then each pair of consecutive interior angles

is supplementary.

Theorem 4-2Consecutive Interior

AnglesIf two parallel

lines are cut by a transversal, then each pair of consecutive interior angles

is supplementary.

34

5 6

Theorem 4-3Alternate Exterior

Angles

Theorem 4-3Alternate Exterior

AnglesIf two parallel

lines are cut by a transversal, then each pair

of alternate exterior angles is congruent.

Theorem 4-3Alternate Exterior

AnglesIf two parallel

lines are cut by a transversal, then each pair

of alternate exterior angles is congruent.

21

8 7

p

rq1 2

3 4

5

6

7

8

.7 find ,1156 If mm

6 7

8 9

t

A B

C D

.9 and ,8 ,7 find ,1286 If mmmm

k

2

1

(4x-5)°

(3x+10)°

b

a

.2 and 1 Find mm

Assignment:

Pgs. 152-153 14-38 evens