The calculated distance (air line) between Pereiaslav and Ruska Poliana is approximately 50 miles respectively 80 kilometers.
By car or train, the actual journey to Ruska Poliana is certainly longer, as only the direct route (as the crow flies) between Pereiaslav and Ruska Poliana has been calculated here.
Air line (approximately)
80 kilometers
43 nautical miles