  We aim to establish and improve the accuracy level of asteroseismic estimates
of mass, radius, and age of giant stars. This can be achieved by measuring
independent, accurate, and precise masses, radii, effective temperatures and
metallicities of long period eclipsing binary stars with a red giant component
that displays solar-like oscillations. We measured precise properties of the
three eclipsing binary systems KIC 7037405, KIC 9540226, and KIC 9970396 and
estimated their ages be $5.3\pm0.5$, $3.1\pm0.6$, and $4.8\pm0.5$ Gyr. The
measurements of the giant stars were compared to corresponding measurements of
mass, radius, and age using asteroseismic scaling relations and grid modeling.
We found that asteroseismic scaling relations without corrections to
$\Delta\nu$ systematically overestimate the masses of the three red giants by
11.7%, 13.7%, and 18.9%, respectively. However, by applying theoretical
correction factors $f_{\Delta\nu}$ according to Rodrigues et al. (2017), we
reached general agreement between dynamical and asteroseismic mass estimates,
and no indications of systematic differences at the precision level of the
asteroseismic measurements. The larger sample investigated by Gaulme et al.
(2016) showed a much more complicated situation, where some stars show
agreement between the dynamical and corrected asteroseismic measures while
others suggest significant overestimates of the asteroseismic measures. We
found no simple explanation for this, but indications of several potential
problems, some theoretical, others observational. Therefore, an extension of
the present precision study to a larger sample of eclipsing systems is crucial
for establishing and improving the accuracy of asteroseismology of giant stars.
