In an equidistant projection, which property is true?

In an equidistant projection, which property is true?

• A. Distances are true only from the center of projection or along a special set of lines
• B. Areas are preserved for continents only
• C. Angles are preserved at most locations
• D. Directions are true along all parallels

Answer: (A)

In an azimuthal equidistant projection, distances from the center of projection to any other point on the map are preserved as true ground distances. This means the map is scaled so that a line drawn from the center to a location represents the real distance along that radial line. Distances between points that don’t lie along those radiating lines or between two non-center points aren’t guaranteed to be true, which is why the statement refers to distances being true from the center or along a special set of lines (the lines radiating from the center). This type of projection is useful for measuring how far you are from a chosen center location, but it doesn’t preserve area or shape in general, and directions or angles aren’t preserved everywhere. That’s why other options about areas, angles, or directions along parallels don’t hold.

In an azimuthal equidistant projection, distances from the center of projection to any other point on the map are preserved as true ground distances. This means the map is scaled so that a line drawn from the center to a location represents the real distance along that radial line. Distances between points that don’t lie along those radiating lines or between two non-center points aren’t guaranteed to be true, which is why the statement refers to distances being true from the center or along a special set of lines (the lines radiating from the center).

This type of projection is useful for measuring how far you are from a chosen center location, but it doesn’t preserve area or shape in general, and directions or angles aren’t preserved everywhere. That’s why other options about areas, angles, or directions along parallels don’t hold.