PDFs of radio galaxy intrinsic proper lengths L and projected proper lengths L_p. If the intrinsic lengths L are Pareto distributed above some cut-off l_min, then their projections on the sky L_p are also Pareto distributed above this cut-off. The tail indices are the same. We show the PDFs f_L(left) and f_Lp(right) for l_min = 0.5 Mpc, l_max = ∞ (see Appendix A) and various tail indices ξ. The support of f_L starts at l_min, which is marked by the vertical grey line in the right panel.