  In this paper we consider the inverse problem of determining, within an
elastic isotropic thick plate modelled by the Reissner-Mindlin theory, the
possible presence of an inclusion made of a different elastic material. Under
some a priori assumptions on the inclusion, we deduce constructive upper and
lower estimates of the area of the inclusion in terms of a scalar quantity
related to the work developed in deforming the plate by applying simultaneously
a couple field and a transverse force field at the boundary of the plate. The
approach allows to consider plates with boundary of Lipschitz class.
