Which lines are parallel if m 3 = m 6?
Justify your answer.

Answer:
[tex]r \parallel s[/tex] by the Converse of the Alternate Interiors Angles Theorem.
Step-by-step explanation:
Remember that two lines are parallel if their angle of direction is the same.
So, in this case we know that [tex]m\angle 3 = m\angle 6[/tex], where [tex]\angle 3[/tex] is the direction of [tex]r[/tex] and [tex]\angle 6[/tex] is the direction of [tex]s[/tex].
Therefore, [tex]r \parallel s[/tex] by the Converse of the Alternate Interior Angles Theorem, which states that if two lines are cut by a transversal and the alternate interior angles are congruent, then those lines are parallel.