2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84404A flat membrane with given shape is displayed; two points in the membrane are randomly selected; the probability that the separation between the points have a specified value is sought. A simple method to evaluate the probability density is developed, and is easily extended to spaces with more dimensions.8 pages, 6 figures, version 2 with corrected commands of figuresBiological PhysicsAstrophysicstext