  The Bell inequalities stand at the cornerstone of the developments of quantum
theory on both the foundational and applied side. The discussion started as a
way to test whether the quantum description of reality is complete or not, but
it developed in such a way that a new research area stemmed from it, namely
quantum information. Far from being and exhausted topic, in the present paper
we present a constructive and geometrically intuitive description of the local
polytope and its facets in a bipartite Bell scenario with two dichotomic
measurements per party.
