A description of ferromagnetic resonance (FMR) modes is given for an exchanged $(F)/(\mathrm{AF})$ bilayer thin films using the static-(AF) model. Included in the analysis are the exchange anisotropy field ${H}_{E},$ the off-aligned exchange coupling angle \ensuremath{\beta}, the in-plane uniaxial, and the cubic magnetocrystalline anisotropies. The resonance field ${H}_{R}$ vs applied field angle \ensuremath{\alpha} curves for an off-aligned exchange system are shifted with respect to the aligned $(\ensuremath{\beta}=0)$ curve; from the experimental measure of the angle ${\ensuremath{\alpha}}_{\mathrm{min}}$ corresponding to the curve minimum, a \ensuremath{\beta} value can be derived. The dispersion relation is described; depending on the frequency range and \ensuremath{\beta} values, up to three modes are expected in the cubic system while one mode at most will appear for the uniaxial one. The linewidth $\ensuremath{\Delta}H$ monotonically increases with H for free (F) layer and aligned exchanged $F/\mathrm{AF};$ for $\ensuremath{\beta}\ensuremath{\ne}0,$ the $\ensuremath{\Delta}H$ vs H curves go through a minimum. A general formula for mode intensity, I, is derived. Taking the rf field h in plane, as the dc field is rotated in plane, the intensity is expected to vanish for an applied field angle ${\ensuremath{\alpha}}_{1}.$ A simple relation between ${\ensuremath{\alpha}}_{1}$ and ${H}_{E}$ is found. For aligned exchange and low-\ensuremath{\beta} values, I decreases monotonically with increasing H, while for a 90\ifmmode^\circ\else\textdegree\fi{} coupling and high-\ensuremath{\beta} values, the I vs H curves go through a maximum; for strong fields all FMR intensities tend to the same asymptotic value. At fixed frequency, the decrease of I with increasing ${H}_{E}$ for the 90\ifmmode^\circ\else\textdegree\fi{}-coupling could be used as a means to distinguish the 90\ifmmode^\circ\else\textdegree\fi{} coupling from the aligned exchange coupling case.