Parallel Lines and 

Transversals

Parallel lines ~ two or more lines that never intersect.  They are always the same distance from each other.

symbol ~ II

Perpendicular line  a pair of lines that intersect at a point and create four right angles.

symbol ~

Transversal  a line that intersects two or more parallel lines.  Three different pairs of angles are created.

Types of  Lines 

2

1 Parallel Lines are lines that never intersect

A transversal is a line that cuts across two or more (usually parallel) lines.

Parallel Lines 

Alternate interior angles  a pair of angles in between the parallel lines and on opposite sides of the same transversal.  They are equal measure.

Examples:

Alternate exterior angles  a pair of angles outside the parallel lines and on opposite sides of the same transversal.  They are equal measure.

Examples:

Corresponding angles  a pair of angles on the same transversal but in the same position on different parallel lines.  They are the same measure.  **think cutting transversal in half and sliding the group of angles down to match other set.

Examples:

Perpendicular Lines  two lines that intersect and form four right angles.  Symbol: 

Example:

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2

34

5

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8

POD  Answer questions in pod book

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9 10 11 12

13 14 15 16

1718

1920

1 2 3 4 5 67 8 9 10 11

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13

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Draw picture in notebook

1.  Name 4 pairs of vertical angles.

2.  Name 4 pairs of alternate interior angles.

3.  Name 4 pairs of alternate exterior angles.

4.  Name 8 pairs of corresponding angles.

5.  Find all angle measures.

Alternate interior CorrespondingVertical  AdjacentAlternate exterior

C

A V

EGA

EGB GHD&

BGH

AGH

GHC DHF

CHF

&

&

&

&

GHC

EGB

EGB

EGA &

A B

C D

E

F

G

H

AI

AE

C

AE

A

AI

V

A

?

?

?

?

?

?

Classify these pairs of angles

http://www.regentsprep.org/Regents/math/geometry/GP8/PracParallel.htm

http://www.classzone.com/cz/books/pre_alg/resources/applications/eWorkbook/index.html

Complete 1  8 in notebook

Eworkbook  Chapter 13  lesson 2

http://www.regentsprep.org/Regents/math/geometry/GP8/PracParallel.htmhttp://www.classzone.com/cz/books/pre_alg/resources/applications/eWorkbook/index.html

123 5

36124

1314

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98

1610

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Attachments

Transversals.pdf

Teacher Notes

© 2009 SMART Technologies ULC

Lesson Objectives & Teacher Notes

Lesson Title Transversals

Subject Mathematics Grade 8 Strand Geometry

Objective Identify the angles formed by transversals.

Page 1 Title page.

Page 2 Review the definition of a transversal. Remind students that a transversal does not necessarily need to cut across two parallel lines (but it usually does.)

Page 3 Explore the angles formed by two parallel lines and a transversal. The angle segments can be dragged. Explain that the angles can be made into pairs of angles. These pairs of angles are given special names.

Page 4 Click on each of the words at the bottom of the page to identify the interior, exterior and alternate angles.

Page 5 Identify alternate interior angles by dragging the angle segments onto the diagram. Drag answers from the right.

Page 6 Identify alternate exterior angles by dragging the angle segments onto the diagram. Drag answers from the right.

Page 7 Identify the corresponding and vertical angles by dragging the angle segments onto the diagram.

Page 8 Identify supplementary and adjacent angles.

Page 9 Identifying each of the angle pairs as: alternate interior, alternate exterior, adjacent, corresponding or vertical.

SMART Notebook

Page 1: Jan 9-9:49 AMPage 2: Dec 20-1:13 PMPage 3: Page 2Page 4: Dec 20-1:13 PMPage 5: Dec 20-1:13 PMPage 6: Feb 22-9:03 AMPage 7: Feb 22-9:31 AMPage 8: Dec 20-1:23 PMPage 9: Dec 20-1:24 PMPage 10: Dec 20-2:42 PMPage 11: Dec 20-2:42 PMPage 12: Jan 9-9:45 AMPage 13: Page 9Page 14: Dec 8-1:29 PMPage 15: Dec 8-1:28 PMPage 16: Dec 8-1:27 PMPage 17: Dec 9-11:13 AMPage 18: Dec 9-1:22 PMPage 19: Dec 9-1:24 PMPage 20: Dec 9-1:25 PMPage 21: Jan 9-9:52 AMPage 22: Dec 8-1:29 PMPage 23: Dec 10-1:04 PMPage 24: Dec 15-1:15 PMPage 25: Jan 11-12:38 PMPage 26: Dec 22-2:13 PMPage 27: Dec 22-2:13 PMPage 28: Jan 9-9:57 AMPage 29: Jan 9-1:34 PMPage 30: Jan 9-1:34 PMPage 31: Jan 9-1:34 PMPage 32: Jan 9-1:34 PMPage 33: Jan 9-1:34 PMAttachments Page 1