Distribution of the velocity dispersion on a random LoS σ_rm, the effective radius R_e, the intrinsic axis ratios p and q and the triaxiality parameter T for the selected ETG sample from them TNG100 simulation. Dashed line represent T = 0.5 in the p − q space and in the 1D histogram of T, which we used to separate the full sample into the “oblate” subsample and the “prolate” subsample.