Given: m || CB Prove: m∠ABC + m∠BAC + m∠ACB = 180° A triangle and line are shown. Line m contains points X and Y. Triangle A B C sits on line M at point A. Line m and line segment B C are parallel. Which statement justifies that angle XAB is congruent to angle ABC? Corresponding angles of parallel lines cut by a transversal are congruent. Vertical angles are congruent. Same-side interior angles of parallel lines cut by a transversal are supplementary. Alternate interior angles of parallel lines cut by a transversal are congruent.