Problem #PRU-34970

Problemas Matemáticas Discretas Combinatoria Dissecciones, particiones, cubiertas y mosaicos Cubiertas Métodos Principio del casillero Principio del casillero (ángulos y longitudes)

Problem

Some open sectors – that is sectors of circles with infinite radii – completely cover a plane. Prove that the sum of the angles of these sectors is no less than \(360^\circ\).