The calculated distance (air line) between Pyeongtaek and Hwawŏn is approximately 114 miles respectively 183 kilometers.
By car or train, the actual journey to Hwawŏn is certainly longer, as only the direct route (as the crow flies) between Pyeongtaek and Hwawŏn has been calculated here.
Air line (approximately)
183 kilometers
99 nautical miles