Question: proofplease be descriptive two lines are parallel and we have...
PROOF-PLEASE be descriptive.
Two lines are parallel and we have a non-perpendicular transversal. We assume conjecture 1 holds, which states that same-side interior angles are supplementary.
We cannot use alternate interior angles are congruent, alternate exterior angles are congruent, corresponding angles are congruent.
Prove: For any set of parallel lines in the plane, alternate interior angles are congruent.