Which angle pair lies outside the two lines on opposite sides of the transversal when the lines are parallel?

Which angle pair lies outside the two lines on opposite sides of the transversal when the lines are parallel?

• A. Alternate exterior angles
• B. Alternate interior angles
• C. Corresponding angles
• D. Vertical angles

Answer: (A)

When a transversal crosses two parallel lines, angles are categorized by location (inside vs outside the lines) and by side of the transversal (same vs opposite). The pair described lies outside the two lines (exterior) and on opposite sides of the transversal (alternate). That makes them alternate exterior angles. This stays consistent with the other types: alternate interior angles are inside the lines on opposite sides, corresponding angles are in the same relative position at each intersection (not both exterior), and vertical angles are opposite angles formed at a single intersection.

When a transversal crosses two parallel lines, angles are categorized by location (inside vs outside the lines) and by side of the transversal (same vs opposite). The pair described lies outside the two lines (exterior) and on opposite sides of the transversal (alternate). That makes them alternate exterior angles.

This stays consistent with the other types: alternate interior angles are inside the lines on opposite sides, corresponding angles are in the same relative position at each intersection (not both exterior), and vertical angles are opposite angles formed at a single intersection.