If two parallel lines are cut by a transversal, which angles are congruent?
Corresponding, alternate exterior and interior, and consecutive interior angles
Alternate interior angels theorem
If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent
Alternate exterior angles theorem
If two parallel lines are cut by a transversal, then the pairs of alternate exterior angels are congruent
Consecutive interior angles theorem
If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary
Corresponding angles converse
If two lines are cut by a transversal so the corresponding angles are congruent, then the lines are parallel
Alternate interior and exterior converse
If two lines are cut by a transversal so the alternate exterior and interior angels are congruent, then the lines are parallel
Consecutive interior angles converse
If two lines are cut by a transversal so the consecutive interior angles are supplementary, then the lines are parallel
Perpendicular postulate