The calculated distance (air line) between Bungo-Takada-shi and Ōita is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to Ōita is certainly longer, as only the direct route (as the crow flies) between Bungo-Takada-shi and Ōita has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles