I heard we have to make a bunch of note cards again.

Yeah, probably one for every type of angle

formed by parallel lines cut by a transversal.

I love math!!!!

At least we don’t have to memorize everything. The

note cards are great on tests!

Parallel lines are lines in the same plane that never intersect.

A transversal is a line that intersects two or more lines in a plane at different points.

There are eight angles formed by the transversalintersecting the lines.

1 2

3 4

5

67

8

Intersecting lines are lines that cross each other. They have a point in common.

A transversal can also intersect intersecting lines.

Eight angles are still formed.

1 2

3 4

5

67

8

Alternate Interior Angles

• opposite sides of the transversal

• both angles are interior angles

• do NOT share a vertex

1 2

3 4

5

67

8

Identify a pair of alternate interior angles.

Consecutive Interior Angles

• same side of the transversal

• both angles are interior angles

• do NOT share a vertex

1 2

3 4

5

67

8

Identify a pair of consecutive interior angles.

WHITE NOTE CARD:

Alternate Interior Angles

• opposite sides of the transversal• both angles are interior angles

• do NOT share a vertex

X

X

0

0

Consecutive Interior Angles

• same side of the transversal

• both angles are interior angles

• do NOT share a vertex

X

X

0

0

Corresponding Angles

• same side of the transversal

• one interior and one exterior angle

• do NOT share a vertex

1 2

3 4

5

67

8

Identify a pair of corresponding angles.

WHITE NOTE CARD:

Corresponding Angles

• same side of the transversal

• one interior angle, one exterior angle

• do NOT share a vertexX

X

0

0

☺

☺

Alternate Exterior Angles

• opposite sides of the transversal

• both exterior angles

• do NOT share a vertex

1 2

3 4

5

67

8

Identify a pair of alternate exterior angles.

Consecutive Exterior Angles

• same side of the transversal

• both exterior angles

• do NOT share a vertex

1 2

3 4

5

67

8

Identify a pair of consecutive exterior angles.

WHITE NOTE CARD:

Alternate Exterior Angles

• opposite sides of the transversal• both angles are exterior angles• do NOT share a vertex

X

X

0

0

Consecutive Exterior Angles

• same side of the transversal

• both angles are exterior angles

• do NOT share a vertexX

X

0

0

If two parallel lines are cut by a transversal, then . . .

• alternate interior angles are congruent.

• consecutive interior angles are supplementary.

• corresponding angles are congruent.

• alternate exterior angles are congruent.

• consecutive exterior angles are supplementary.

Add this information about the relationship between the angle measures to each note card.

If the lines cut by a transversal are NOT parallel, then no relationship exists between the pairs of angles EXCEPT vertical angles. Vertical angles are always congruent.

1 2

3 4

5

67

8

100° 2

3 4

5

67

8

a // b and c is the transversal.

a

b

c

Find the measure of each angle. Explain how you determined the measure.

1 95°

3 4

5

67

8

x // y and z is the transversal. What other angle measures can you find?

x

y

z

Are we done with the note cards yet?

Yes, now it is time to solve some

equations!