Parallel lines and transversals

Corresponding Angles

These angles occupy corresponding positions in relation to the transversal.

Alternate Interior Angles

angles between 2 lines and on opposite sides of a transversal

Alternate Exterior Angles

Angles that lie outside a pair of lines and on opposite sides of a transversal.

Consecutive Interior Angles

angles that are on the same side of the transversal and inside the two lines

Consecutive Exterior Angles

Pairs of angles formed when a third line (transversal) crosses two other lines. The angles are on the same side of the transversal and outside the other two lines.

Corresponding Angles Postulate

If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent.

Alternate Interior Angles Theorem

If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent.

Consecutive Interior Angles Theorem

If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary.

Alternate Exterior Angles Theorem

If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent

Vertical angles

Two nonadjacent angles formed by two intersecting lines