Answer:
parallel lines a and b
parallel lines l and m
Step-by-step explanation:
25 A.
Angles 3 and 7 are alternate interior angles of lines a and b cut by transversal l.
Since angles 3 and 7 are congruent, lines a and b are parallel by the theorem:
<em>If two lines are cut by a transversal such that alternate interior angles are congruent, then the lines are parallel.</em>
25 B.
Angles 5 and 12 are same side interior angles of lines l and m and transversal b.
Since the sum of the measures of the angles 5 and 12 is 180, then angles 5 and 12 are supplementary angles making lines l and m parallel by the theorem:
<em>If two lines are cut by a transversal such that same side interior angles are supplementary, then the lines are parallel.</em>