In an equal-area map projection, which feature is proportional to the corresponding area on Earth?

• A. Areas on the map are proportional to corresponding areas on Earth
• B. Distances on the map are preserved from the center
• C. Angles are preserved at every point
• D. Directions are preserved along features

Answer: (A)

Equal-area projections keep the size of regions on the map in the same proportion as their real sizes on Earth. In other words, area on the map scales with Earth’s area by a constant factor, so larger regions appear larger and smaller regions appear smaller in the true size relationship. The trade-off is that shapes are often distorted, and distances or angles aren’t reliably preserved. So the feature that matches the Earth’s area most faithfully on the map is that areas on the map are proportional to the corresponding areas on Earth.