What are contour lines?

• A. Lines that indicate road centers
• B. Lines that connect points of equal elevation
• C. Lines that model water flow
• D. Lines that mark political boundaries

Answer: (B)

Contour lines are lines on a map that connect points at the same elevation above a reference level, usually mean sea level. They appear on topographic maps to represent the shape of the terrain. If you walk along a contour line, your elevation stays the same; moving across lines means you’re going up or down. The distance between lines, called the contour interval, shows how steep the land is—lines that are close together indicate a steep slope, while lines that are spaced farther apart indicate a gentler slope. Contour lines typically form closed loops, with inner loops representing hills or ridges and other patterns showing valleys and depressions. They don’t indicate roads or political boundaries; those are shown with different map features.