  It is shown that an embedding of the general relativity $4-$space into a flat
$12-$space gives a model of gravitation with the global $U(1)-$symmetry and the
discrete $D_{1}-$one. The last one may be transformed into the $SU(2)-$symmetry
of the unified model, and the demand of independence of $U(1)-$ and
$SU(2)-$transformations leads to the estimate $\sin^{2}\theta_{min}=0,20$ where
$\theta_{min}$ is an analog of the Weinberg angle of the standard model.
