The calculated distance (air line) between Dien Bien Phu and Hà Đông is approximately 180 miles respectively 289 kilometers.
By car or train, the actual journey to Hà Đông is certainly longer, as only the direct route (as the crow flies) between Dien Bien Phu and Hà Đông has been calculated here.
Air line (approximately)
289 kilometers
156 nautical miles