The calculated distance (air line) between Tuyên Quang and Thái Nguyên is approximately 44 miles respectively 70 kilometers.
By car or train, the actual journey to Thái Nguyên is certainly longer, as only the direct route (as the crow flies) between Tuyên Quang and Thái Nguyên has been calculated here.
Air line (approximately)
70 kilometers
38 nautical miles