In map projections, which property is preserved by a conformal projection at a small scale?

• A. Angles
• B. Areas
• C. Distances
• D. Volumes

Answer: (A)

Conformal projections preserve angles locally. At a very small scale, the map behaves like a similarity transformation, so the scale is the same in all directions at a point. This means tiny shapes stay looking like their actual shapes and intersections keep their angles, which is why angles are preserved on such maps. Distances and areas aren’t kept stable because the scale factor varies from place to place across the map, causing local stretching or compression. Volumes, being a spatial concept for three dimensions, don’t have a meaningful counterpart on a 2D projection. So the property kept at small scales is the preservation of angles.