Question: What can be concluded if two angles are supplementary and one of them is an exterior angle formed by a transversal intersecting two parallel lines?

Options:

1. They are both acute.
2. They are both obtuse.
3. One is an interior angle.
4. They are equal.

Correct Answer: One is an interior angle.

Solution:

If one angle is an exterior angle formed by a transversal intersecting two parallel lines, the other angle must be an interior angle, as they are supplementary.