Light scattering in the Wentzel-Kramers-Brillouin (WKB) approximation is considered from the point of view of stereology. The extinction and absorption cross sections for an ensemble of chaotically oriented particles of arbitrary shape are expressed analytically through the chord length distribution. The analytical approximation for the scattering phase function is proposed. The derived analytical expressions are compared to the calculations with the discrete-dipole-approximation method.