The calculated distance (air line) between Twimoraet’ŏ and Kanggye is approximately 144 miles respectively 232 kilometers.
By car or train, the actual journey to Kanggye is certainly longer, as only the direct route (as the crow flies) between Twimoraet’ŏ and Kanggye has been calculated here.
Air line (approximately)
232 kilometers
125 nautical miles