  In modeling the X-ray spectra of active galactic nuclei (AGNs), the
inclination angle is a parameter that can play an important role in analyzing
the X-ray spectra of AGN, but it has never been studied in detail. We present a
broadband X-ray spectral analysis of the joint NuSTAR-XMM-Newton observations
of 13 sources with [OIII] measured inclinations determined by Fischer et al.
2013. By freezing the inclination angles at the [OIII] measured values when
modeling the observations, the spectra are well fitted and the geometrical
properties of the obscuring structure of the AGNs are slightly better
constrained than those fitted when the inclination angles are left free to
vary. We also test if one could freeze the inclinations at other specific
angles in fitting the AGN X-ray spectra as commonly did in the literatures. We
find that one should always let the inclination angle free to vary in modeling
the X-ray spectra of AGNs, while fixing the inclination angle at [OIII]
measured values and fixing the inclination angle at 60$^\circ$ also present
correct fits of the sources in our sample.Correlations between the covering
factor and the average column density of the obscuring torus with respect to
the Eddington ratio are also measured, suggesting that the distribution of the
material in the obscuring torus is regulated by the Eddington ratio, which is
in agreement with previous studies. In addition, no geometrical correlation is
found between the narrow line region of the AGN and the obscuring torus,
suggesting that the geometry might be more complex than what is assumed in the
simplistic unified model.
