[en] Experimental data for elastic and inelastic scattering of ¹¹B ions by ¹²C nuclei measured recently at the Warsaw Cyclotron were analyzed by means of the coupled-reaction-channel method. Rotational model for the low-lying states in ¹¹B and ¹²C was assumed. The deformation lengths for the ¹¹B and ¹²C ground states as well as for the ¹¹B 3/2^- excited state (Ex 5.02 MeV) were extracted from the analysis. Contrary to the theoretical predictions the deformation length of the ¹¹B 3/2^- excited state was found to be large, close to that of the ground state. (author)