Had to check. You'd be surprised what people overlook.
Reaxys search turns up two references for the dielectric constant of 1H-imidazole:
Minkin et al. Zhurnal Fizicheskoi Khimii vol. 36, 1962, pp 469
Roussy. Journal de Chimie Physique et de Physico-Chimie Biologique vol. 64, 1967. pp 529
Not finding anything regarding 1,2,3-triazole.