Parallel Line Proofs

Front

What is the Transitive Property?

Back

If two angles are each congruent to a third angle, then they are congruent to each other.

Front

What is the definition of supplementary angles?

Back

Two angles are supplementary if the sum of their measures is 180 degrees.

Front

What does it mean for a segment to be bisected?

Back

A segment is bisected when it is divided into two equal parts.

Front

What can be concluded if ∠1 ≅ ∠3?

Back

If ∠1 ≅ ∠3, then line a is parallel to line b.

Front

What does the Alternate Exterior Angles Theorem state?

Back

If two parallel lines are cut by a transversal, then each pair of alternate exterior angles is congruent.

Front

What is the definition of congruent angles?

Back

Angles that have the same measure are called congruent angles.

Front

What is the Corresponding Angles Theorem?

Back

If two parallel lines are cut by a transversal, then each pair of corresponding angles is congruent.

Front

What is the definition of complementary angles?

Back

Two angles are complementary if the sum of their measures is 90 degrees.

Front

What is the Reflexive Property?

Back

A quantity is equal to itself; for example, segment AB is congruent to segment AB.

Front

What is the Angle Addition Postulate?

Back

If point B is in the interior of ∠AOC, then ∠AOB + ∠BOC = ∠AOC.