Question

when a transversal crosses a pair of parallel lines, which types of angle pairs are supplementary?
a. alternate interior
b. same - side interior
c. alternate exterior
d. vertical

Explanation:

• Recall the properties of angles formed by a transversal and parallel lines:
• Alternate interior angles are congruent (equal), not supplementary. So option A is incorrect.
• Same - side interior angles: When a transversal intersects two parallel lines, same - side interior angles are supplementary (their sum is \(180^{\circ}\)).
• Alternate exterior angles are congruent, not supplementary. So option C is incorrect.
• Vertical angles are congruent, not supplementary. So option D is incorrect.

Answer:

B. same - side interior