Moon Dust, thanks for trying the challenge, maybe not at the moment but at some stage I know you will be able to do it. It is a hard challenge.
Dark, I don't think any poem can be successful written without it having some kind of inner meaning to the writer, try to write something and remove yourself from the poem if at all possible, try to keep the poem from being self-analytic. IT is hard challenge and I don't know if I can complete this one myself, with the dreaded writer's block. Here is one that might qualify from my notebooks. http://piptalk.com/pip/Forum50/HTML/000002.html
The sum of the angles of that rectangle is too monstrous to contemplate!