Viewing angle versus polarization fraction relation for the MACS J0717.5+3745 relic. A viewing angle of 90° implies that the merger is in the plane of the sky (i.e., perpendicular to the shock). The four solid curves, that are nearly identical, give the theoretical predictions for spectral indices of α = −1.18, −1.13, −1.17, and −1.16, for the relic subregions. The triangle, circle, star, and square provide the corresponding estimates for the relic subregions R1, R2, R3, and R4. The dashed lines indicate the minimum and maximum value of the mean polarization fraction and the viewing angle. The possible viewing angles of MACS J0717.5+3745 fall inside the green shaded region. The plot shows that the relic in MACS J0717.5+3745 is seen to be less edge-on.