Below is a two-column proof incorrectly proving that the three angles of δpqr sum to 180°: statements reasons draw line zy parallel to segment pq construction m∠zrp + m∠prq + m∠qry = m∠zry angle addition postulate ∠zrp ≅ ∠rpq alternate interior angles theorem ∠qry ≅ ∠pqr alternate interior angles theorem m∠rpq + m∠prq + m∠pqr = m∠zry substitution m∠zry = 180° definition of a straight angle m∠rpq + m∠prq + m∠pqr = 180° additive property of equality which statement will accurately correct the two-column proof?