The calculated distance (air line) between Sa'dah and Bayt al Faqīh is approximately 170 miles respectively 274 kilometers.
By car or train, the actual journey to Bayt al Faqīh is certainly longer, as only the direct route (as the crow flies) between Sa'dah and Bayt al Faqīh has been calculated here.
Air line (approximately)
274 kilometers
148 nautical miles