Question

Is it correct, that the distance from vector \[v=(1,3,5)\] onto the subspace \[U=span(u) \] in \[R^3\], where \[u=(1,-1,1)\] is 5,8? I found the projection first to \[Proj=(0.25,-0.25,0.25)\] and then the length \[||v-Proj||=5,8\]