Linked from
The 9 pages that link to Distance formula, each with the reason it gives.
CircleRelated: Applying it to the center yields the circle equation.
Analytic geometryRelated: It converts coordinate differences into geometric lengths.
Line segmentRelated: It calculates a segment’s length from the coordinates of its endpoints.
Nth rootRelated: Euclidean distance is a square root of the sum of squared coordinate differences.
Solid geometryRelated: It measures lengths between vertices and other points in space.