Distance
Path Length
The other meaning of distance is the length of a path. This is easily understood if the path consists entirely of line segments, such the perimeter of a pentagon. The distance is the sum of the lengths of the line segments that make up the perimeter. For curves that are not line segments, a continuous path can usually be approximated by a sequence of line segments. Using shorter line segments produces a better approximation. The limiting case, when the lengths of the line segments go to zero, is the distance. A common example would be the circumference of a circle, which is a distance.
Kristin Lewotsky
Additional topics
Science EncyclopediaScience & Philosophy: Direct Variation to DysplasiaDistance - Path length