The calculated distance (air line) between Ksar El Kebir and Sidi Slimane is approximately 51 miles respectively 82 kilometers.
By car or train, the actual journey to Sidi Slimane is certainly longer, as only the direct route (as the crow flies) between Ksar El Kebir and Sidi Slimane has been calculated here.
Air line (approximately)
82 kilometers
44 nautical miles