Problem #PRU-58084

Problemas Geometría Geometría plana Círculos Círculo, sector, segmento, etc. Métodos Principio del casillero Principio del casillero (ángulos y longitudes) Principio del casillero (número finito de puntos, líneas, etc.)
 12–13  4.0

Problem

There are 25 points on a plane, and among any three of them there can be found two points with a distance between them of less than 1. Prove that there is a circle of radius 1 containing at least 13 of these points.