McDougal Littel, Chapter 3: These are the postulates and theorems from sections 3.2 & 3.3 that you will be using in proofs.
Postulate 15 Corresponding Angle s Postulate
If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent.
Postulate 16 Corresponding Angle s Converse
If two lines are cut by a transversal such that coresponding Angle s are congruent, then the lines are parallel.
Theorem 3.1 Alternate Interior Angles Theorem
If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent.
Theorem 3.4 Alternate Interior Angles Converse
If two lines are cut by a transversal such that the pairs of alternate interior angles are congruent, then the lines are parallel.
Theorem 3.2 Alternate Exterior Angles Theorem
If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent.
Theorem 3.5 Alternate Exterior Angles Theorem
If two parallel lines are cut by a transversal such that the pairs of alternate exterior angles are congruent, then the lines are parallel
Theorem 3.3 Consecutive Interior Angles Theorem
If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary.
Theorem 3.6 Consecutive Interior Angles Converse
If two lines are cut by a transversal such that the consecutive interior angles are supplementary, then the lines are parallel.
Theorem 3.7 Transitive Property of Parallel Lines
If two lines are parallel to the same line, then they are parallel to each other
