Parallels
Corresponding Angles
If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent.
Corresponding Angles Converse
If two lines are cut by a transversal and the corresponding angles are congruent, the lines are parallel.
Alternate Interior Angles
If two parallel lines are cut by a transversal, then the alternate interior angles are congruent.
Alternate Exterior Angles
If two parallel lines are cut by a transversal, then the alternate exterior angles are congruent.
Interiors on Same Side If two parallel lines are cut by a transversal, the interior angles on the same side of the transversal are supplementary.
Alternate Interior Angles Converse
If two lines are cut by a transversal and the alternate interior angles are congruent, the lines are parallel.
Alternate Exterior AngleConverse
If two lines are cut by a transversal and the alternate exterior angles are congruent, the lines are parallel.
Interiors on Same Side Converse
If two lines are cut by a transversal and the interior angles on the same side of the transversal are supplementary, the lines are parallel.