  We prove that when n >= 5, the Dehn function of SL(n;Z) is quadratic. The
proof involves decomposing a disc in SL(n;R)/SO(n) into triangles of varying
sizes. By mapping these triangles into SL(n;Z) and replacing large elementary
matrices by "shortcuts," we obtain words of a particular form, and we use
combinatorial techniques to fill these loops.
