Parallel Lines
Parallel Lines and Transversals
Special Angle Relationships
Proving Lines Parallel
Linear Pairs/Vertical Angles
100
Sometimes, always, or never?
Parallel lines ______ intersect.
Never
100
If two parallel lines are cut by a transversal, what is the relationship between the same consecutive interior angles formed?
Same side interior angles add up to 180.
100
If two parallel lines are cut by a transversal, what is the relationship between the corresponding angles formed?
Corresponding angles are congruent.
100
Two lines are cut by a transversal. If angles A and B are corresponding and the measure of angle A is 80 degrees and the measure of angle B is 90, does that prove that the lines are parallel? Why?
No. Angles A and B must be congruent.
100
Fill in the blank:
Vertical angles are ______
Linear pairs are _______
Congruent
Supplementary
200
Sometimes, always, or never?
Lines cut by a transversal are _________ parallel.
Sometimes
200
If two parallel lines are cut by a transversal, what is the relationship between the alternate interior angles formed?
Alternate interior angles are congruent.
200
If two lines are parallel and cut by a transversal, then same side interior angles are _____________.
Name and angle measure.
Supplementary, 180 degrees
200
Two lines are cut by a transversal. If angles A and B are same side interior angles and the measure of angle A is 80 degrees and the measure of angle B is 100, does that prove that the lines are parallel? Why?
Yes. Same side interior angles add up to 180 degrees.
200
What is the value for x in the diagram. Explain what angle relationship you used. 
128 degrees, because they are vertical angles which are always congruent
300
Sometimes, always, or never?
Vertical angles are congruent.
Always
300
If two parallel lines are cut by a transversal, what is the relationship between the vertical angles formed?
Vertical angles are congruent.
300
If two parallel lines are cut by a transversal, and alternate interior angles are congruent, and if one of those alternate interior angles is x+15, and the other is 2x+5.
What is the value of x?
x = 10
300
Two lines are cut by a transversal. If angles A and B are alternate interior angles and the measure of angle A is 80 degrees and the measure of angle B is 100, does that prove that the lines are parallel? Why?
No. Alternate interior angles are congruent.
300
Find the value of x and explain what angle relationship you used to reach your answer.
x = 63
400
Line A is parallel to line B, and line B is parallel to line C. Is line A parallel to line C?
Yes.
400
If two parallel lines are cut by a transversal, what is the relationship between the same side exterior angles formed?
Consecutive exterior angles add up to 180.
400
If two parallel lines are cut by a transversal, then same side interior angles are supplementary, and if one of those same side interior angles is 3x+4 and the other is 2x+6,
Find the value of x
x=34
400
Two lines are cut by a transversal. If angles A and B are same side exterior angles and the measure of angle A is 80 degrees and the measure of angle B is 80, does that prove that the lines are parallel? Why?
No. Same side exterior angles must be supplementary.
400
Solve for x: 
x = 38
500
Describe a real-world example or model of parallel lines.
Ex: Skis on a skier's feet.
500
Two parallel lines are cut by a transversal. If Angles 3 and 4 are alternate exterior angles and the measure of angle 3 is 80 degrees, what is the measure of angle 4?
80 degrees
500
If two lines are parallel and cut by a transversal, then same side interior angles are supplementary, and if one of those interior angles is 7x+12 and the other is 3x+8...
What are the measures of each angle?
56 degrees and 124 degrees
500
Two lines are cut by a transversal. If angles A and B are same side exterior angles and are supplementary, does that prove that the lines are parallel? Why?
Yes. Same side exterior angles are supplementary.
500
Solve for x: 
x = 15