Which line is perpendicular to the horizon?

Which line is perpendicular to the horizon?

• A. Vertical
• B. Horizontal
• C. Diagonal
• D. Curved

Answer: (A)

Perpendicular means forming a right angle to another line. The horizon is horizontal, so the line that goes straight up and down is the one that meets it at 90 degrees. That up-and-down orientation is called vertical. A horizontal line runs left to right and would be parallel to the horizon, not perpendicular. A diagonal line crosses at an angle other than 90 degrees, and a curved line isn’t a straight orientation, so it isn’t described as perpendicular to the horizon.

Perpendicular means forming a right angle to another line. The horizon is horizontal, so the line that goes straight up and down is the one that meets it at 90 degrees. That up-and-down orientation is called vertical. A horizontal line runs left to right and would be parallel to the horizon, not perpendicular. A diagonal line crosses at an angle other than 90 degrees, and a curved line isn’t a straight orientation, so it isn’t described as perpendicular to the horizon.