  We prove an additivity for evenly (oddly) finite dimensional objects in
distinguished triangles in a triangulated monoidal category structured by an
underlying model monoidal category. In particular, the result holds in the
Q-localized motivic stable homotopy category of spectra and in Q-localized
Voevodsky's category of motives over a field, char=0. As an application, we
show that the motives of schemes of dimension one (separated and of finite type
over a field, char=0) are finite dimensional.
