Segment Addition Postulate (SAP)
If B is between A and C, then AB+BC=AC
Angle Addition Postulate
If point B lies in the interior of <AOC, then m<AOB+m<BOC=m<AOC
Vertical Angles Theorem
Vertical angles are congruent
If two parallel line are cut by a transversal, then corresponding angles are congruent.
If two parallel lines are cut by a transversal, then alternate interior angles are congruent
If two parallel lines are cut by a transversal, then same-side interior angles are supplementary.
If a transversal is perpendicular to one of the two parallel lines, then it is perpendicular to the other one also.