2-1 Reteach to Build Understanding Parallel Lines 1. Use the diagrams to fill in the blanks. Determine whether the pair of angles congruent or supplementary and find the measure of the angle. Corresponding Angles Same-Side Interior Angles 21 and 22 are congruent If m/1 = 100, then m2 = Alternate Interior Angles F 21 and 22 are 21 and 22 are congruent sorguent. If mz1 = 75°, then If m1 = 82°, then m22= mz2 = 2. A student said that m/1 = 80°. What error did the student likely make? What is m<1? Alternate Exter Angles 21 and 22 are It mc1= 77, then m 2 =>