What are contour lines used for on maps?

• A. Contour lines show relief or elevation on a topographic map.
• B. Contour lines show rainfall patterns
• C. Contour lines indicate political boundaries
• D. Contour lines mark vegetation types

Answer: (A)

Contour lines are used to represent the shape of the land by connecting points that are at the same elevation. This reveals relief on a topographic map—the heights of hills and depths of valleys—and shows how steep or gentle the terrain is based on how tightly the lines are spaced. They do not depict rainfall patterns, political boundaries, or vegetation types; those features require other symbols or data. So contour lines are the tool that communicates elevation and terrain form on maps.