Distribution of the angle difference between nebular position angle and radio jet position angle, |θ − PA_radio|. The blue histogram shows the number distribution of flux-weighted angle difference, |θ_weight − PA_radio| (sensitive to high surface brightness nebula morphology). The magenta histogram represents the unweighted measurements, |θ_unweight − PA_radio| (quantifying the morphology of the whole nebula). The values are presented in Table 3. We mark the obvious outliers in the two distributions in corresponding colours. This shows that most of our HzRGs have their Lyα nebula elongated along the jet axis.