Which statement about map projections best describes their distortion of geometry?

• A. All projections preserve both area and distance.
• B. Mercator projections preserve area near poles.
• C. Equal-area projections preserve area but distort shape.
• D. Some projections can preserve distance perfectly everywhere.

Answer: (C)

When we flatten the Earth's curved surface onto a map, we have to choose which geometric property to keep and which to bend. Equal-area projections are designed to keep the size of regions proportional to their real areas, so the areas look correct on the map. To achieve that, their shapes inevitably get distorted—regions can appear stretched, squashed, or oddly shaped in order to preserve area across the map. This trade-off is why equal-area maps are useful for comparing how much land different regions cover, even though their outlines aren’t perfectly true to form. In contrast, projections that preserve shapes locally (conformal maps like Mercator) keep angles and small shapes intact but distort area, especially near the poles, showing that you can’t have perfect accuracy for both area and shape simultaneously. And no projection can preserve distances perfectly everywhere, because flattening a curved surface inevitably warps distances somewhere. So the idea that equal-area projections keep area intact while distorting shape accurately describes how distortion in geometry is managed by these maps.