



 
A net is simply any collection of polygons P(1)...P(n) in the plane that corresponds to the faces F(1)...F(n) of a polyhedron (for each i, P(i) and F(i) must be the same shape and size); is connected; and is such that if two polygons P(i),P(j) share an edge, then so do F(i) and F(j). Thus, by adding more joined edges the net can be folded into a polyhedron. Alternatively, by cutting edges the polyhedron can be folded flat in the plane without coming apart. There is no easy rule for finding nets; indeed it is a very difficult open problem to determine whether there always is a net. For simple polyhedra it is usually not too difficult and there are usually many ways to do it. For your rectangular prism, start by drawing one of the square ends; draw (for instance) the four rectangular faces joined to it; then put the last (square) face on. Make sure all the faces you join in the net will be joined in the polyhedron! Good Hunting!  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 