Question

What theorem proves lines are parallel?

Answer 1

Parallel lines: The two lines that do not intersect at any point are called parallel lines.

Theorems that prove that lines are parallel:

If a pair of alternate angles formed by a transversal of two lines are congruent then the two lines are parallel.

If two lines in a plane are parallel to a third line in the plane then those two lines are parallel to each other.

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

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