  We derive analytical results for the large-time relaxation of the Sherrington
- Kirkpatrick model in the thermodynamic limit, starting from a random
configuration. The system never achieves local equilibrium in any fixed sector
of phase-space, but remains in an asymptotic out of equilibrium regime. We
propose as a tool, both numerical and analytical, for the study of the out of
equilibrium dynamics of spin-glass models the use of `triangle relations' which
describe the geometry of the configurations at three (long) different times.
