  We report on a confined quark model calculation of the transition form
factors for the radiative decays of \eta(\eta')->\gamma l^+l^- and
\eta(\eta')->\gamma\pi^+\pi^-. The \eta-\eta' mixing angle \theta_P is
determined from the set of data on the electromagnetic \eta(\eta') decays. It
is found that \theta_P\sim -16.5. The analysis of the dipionic mass
distribution in the decay \eta'->\gamma\pi^+\pi^- confirms the existence of a
non-resonant contribution which is the box anomaly.
