Magdalena left out a statement from the proof shown. Which statement is best explained by the alternate exterior angles theorem? Given a is parallel to b and c is parallel to d, prove angle 1 is congruent to angle 3. Lines a b cut through lines c and d. The top left angle formed by a and c is labeled 1, the top right angle formed by b and c is 2, and the bottom right angle formed by b and d is 3. A 2-column table with 5 rows. Column 1 is labeled statement with entries a is parallel to b, angle 1 is congruent to angle 2, c is parallel to d, question mark, if angle 1 is congruent to angle 2 and angle 2 is congruent to angle 3 then angle 1 is congruent to angle 3. Column 2 is labeled reason with entries given, corresponding angles postulate, given, alternate exterior angles theorem, transitive property of equality. CLEAR CHECK 23 m1+m2=180 a and b are both lines. 2 and 3 are supplementary