The differential cross sections of the 12 C( 3 He,t) 12 N reaction leading to formation of the 1 + (ground state), 2 + (0.96 MeV), 2 − (1.19 MeV), and 1 − (1.80 MeV) states of 12 N are measured at E( 3 He)=40 MeV. The analysis of the data is carried out within the modified diffraction model (MDM) and distorted wave Born approximation (DWBA). Enhanced rms radii were obtained for the ground, 2 − (1.19 MeV), and 1 − (1.80 MeV) states. We revealed that 12 B, 12 N, and 12 C in the IAS with T=1, and spin-parities 2 − and 1 − have increased radii and exhibit properties of neutron and proton halo states.