What term means the number of coordinates used to express a position?

• A. Coordinate
• B. Dimension
• C. Vector
• D. Plane

Answer: (B)

Dimensionality is the number of coordinates needed to specify a position. For a point on a line you only need one coordinate, in a plane you need two, and in space you need three. That count—the number of coordinates required to locate a point—is what we call the dimension.

A coordinate is each individual number used to pin down the location, not the overall count itself. A vector is a quantity with magnitude and direction, often described by coordinates but not the count of coordinates. A plane is a flat two-dimensional surface, which relates to two coordinates for points on it but does not define the concept of how many coordinates are needed.