PROBLEM OF THE MONTH
December 2006
Is there a polyhedron and a point outside of it, from which no vertex of the polyhedron is visible? The same question for a convex polyhedron? Justify your answers.
Recall that a polyhedron is a connected set obtained as a union of finitely many convex polyhedra. For example, if we remove a small cube from the interior of a bigger cube, then we obtain a (non-convex) polyhedron.
This month's prize will be awarded to the best explained, correct solution.
Closing date: January 1st at 12 pm.