The diagram you've uploaded shows two lines intersected by a transversal. The question asks what must be true for the two lines to be parallel.

In this scenario, angles 3 and 5 are corresponding angles. According to the Corresponding Angles Postulate, when a transversal crosses two parallel lines, corresponding angles are congruent.

So, the correct answer is:

• Angles 3 and 5 must be congruent.

This would make the lines parallel.

Would you like further details or have any questions about this? Here are 5 related questions to expand on this topic:

1. What are alternate interior angles, and how do they relate to parallel lines?
2. What other pairs of corresponding angles can be identified in this diagram?
3. Can two lines be parallel if the corresponding angles are not congruent?
4. How does the converse of the Corresponding Angles Postulate work?
5. What is the difference between supplementary and complementary angles?

Tip: Always remember that corresponding angles are equal when lines are parallel, and this property is often used to prove parallelism!