Parallel Lines Converse

If two lines cut by a transversal have supplementary consecutive exterior angles, what can we conclude about them?

• Perpendicular

• Intersecting

• Parallel

• Collinear

If two lines cut by a transversal have congruent alternate interior angles, can we conclude that they are parallel? (True/False)

• Sometimes

• True

• Not enough information

• False

If two lines cut by a transversal have congruent alternate exterior angles, can we conclude that they are parallel? (True/False)

• True

• Sometimes

• False

• Not enough information

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Consecutive interior angles theorem

• Consecutive interior angles converse

Using the given, determine if the conclusion is valid. If so, justify it.
Given:

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Consecutive interior angles theorem

• Consecutive interior angles converse

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Consecutive interior angles theorem

• Consecutive interior angles converse

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Consecutive interior angles theorem

• Consecutive interior angles converse

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Corresponding angles postulate

• Corresponding angles converse

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Corresponding angles postulate

• Corresponding angles converse

Using the given, determine if the conclusion is valid. If so, justify it.
Given:

• Not valid

• Alternate interior angles theorem

• Alternate interior angles converse

• Alternate exterior angles theorem

• Alternate exterior  angles converse