Given an n-gon made of meccano, how many extra pieces of meccanno would be needed to brace it so that it cannot flex if they must be placed on the exterior?

I suspect that, if the n-gon is regular and convex the answer is n-1, except when n=3 and no meccano pieces are needed, and that, if it is allowed to be concave, there exists an n-gon for all n which can be braced with n-3 pieces because n-3 pieces will triangulate the interior of any n-gon, and that there exists a convex n-gon for all n>5 which can be braced with

Last edited by namealreadychosen (2011-08-29 18:01:54)