Geometry/Trig
Name: ______________________________
Date: _______________________________
Lesson 8-1 Parallel Line Theorems
Learning Goal: What are the names and relationships of angle pairs formed by parallel lines and a transversal?
Do Now
Using the picture below, determine the measure of each angle that’s listed.
Activate our knowledge!
What are parallel lines?
New Vocab ALERT!
Symbol for parallel:
Transversal:
When a transversal intersects parallel lines
Special angle pairs are formed that are named by their location and have special relationships

Geometry/Trig

Geometry/Trig

Geometry/Trig
Shortcut!
1.
When parallel lines are cut by a transversal, any pair of angles is either
___________________________________ or __________________________________________________.
2.
Any pairs that are Alternate are ____________________________.
3.
Any pairs that are “Same Side” are _____________________________________.

Geometry/Trig
Try some examples!
Identify what type of angles is indicated in each diagram, then tell me what relationship they have.
Type of Angles:
Relationship:
Type of Angles:
Type of Angles:
Relationship:
Type of Angles:
Relationship: Relationship:
2. For each diagram below, (a) state the type of angles indicated, (b) state the relationship between these angles, and (c) find the missing angle value.
Type: _________________________
Type: _________________________
Relationship: ____________________
Relationship: ____________________
Missing Angle:
Missing Angle:
Type: _________________________
Relationship: ____________________
Missing Angle:
Type: _________________________
Relationship: ____________________
Missing Angle:

Geometry/Trig
State the type of angles shown in each diagram below (alternate interior, alternate exterior, same side interior, same side exterior, or corresponding), then state the relationship between them (congruent or supplementary) and find the missing angle.
Type:
________________________________
Relationship:
______________________________
Missing Angle:
_____________________________
Type:
________________________________
Relationship:
______________________________
Missing Angle:
_____________________________
Type:
________________________________
Relationship:
______________________________
Missing Angle:
_____________________________

1.
Geometry/Trig
Type: _______________________________
Relationship: ________________________
Missing Angle:
3.
5.
Type: _______________________________
Relationship: ________________________
Missing Angle:
2.
4.
6.
Type: _______________________________
Relationship: ________________________
Missing Angle:
Type: _______________________________
Relationship: ________________________
Missing Angle:
Type: _______________________________
Relationship: ________________________
Missing Angle:
Type: _______________________________
Relationship: ________________________
Missing Angle: