Given, Height of the transmitting antenna, HT=33.8m HT=0.0338km Height of the receiving antenna, HR=64.8m⇒HR=0.0648km Radius of earth, R=6400km As we know, dmax=√2×R×H For both antennas, dmax=‌√2×6400×0.0338 ‌+√2×6400×0.0648 dmax=‌√12800×0.0338 ‌+√12800×0.0648 dmax=‌49.6km The maximum distance between the antennas for satisfactory communication in line of sight mode is 49.6 km .