3-2 geometry

theorem 3-3: alternate exterior angles theorem

if a transversal intersects two parallel lines, then alternate exterior angles are congruent.

theorem 3-1: alternate interior angles theorem

if a transversal intersects two parallel lines, then alternate interior angles are congruent.

theorem 3-2: corresponding angles theorem

if a transversal intersects two parallel lines, then corresponding angles are congruent.

postulate 3-1: same-side interior angles postulate

if a transversal intersects two parallel lines, then same-side interior angles are supplementary.

theorem 3-7: converse of the alternate exterior angles theorem

if two lines and a transversal form alternate exterior angles that are congruent, then the two lines are parallel.

theorem 3-5: converse of alternate interior angles theorem

if two lines and a transversal form alternate interior angles that are congruent, then the two lines are parallel.

theorem 3-4: converse of the corresponding angles theorem

if two lines and a transversal form corresponding angles that are congruent, then the lines are parallel.

theorem 3-6: converse of the same-side interior angles postulate

if two lines and a transversal form same-side interior angles that are supplementary, then the two lines are parallel.

theorem 3-8

if two lines are parallel to the same line, then they are parallel to each other.

theorem 3-10: perpendicular transversal theorem

in a plane, if a line is perpendicular to one of two parallel lines, then it is also perpendicular to the other.

theorem 3-9

in a plane, if two lines are perpendicular to the same line, then they are parallel to each other.