The calculated distance (air line) between Panghyŏn-dong and Kanggye is approximately 103 miles respectively 166 kilometers.
By car or train, the actual journey to Kanggye is certainly longer, as only the direct route (as the crow flies) between Panghyŏn-dong and Kanggye has been calculated here.
Air line (approximately)
166 kilometers
89 nautical miles