The calculated distance (air line) between Dinard and Vern-sur-Seiche is approximately 46 miles respectively 74 kilometers.
By car or train, the actual journey to Vern-sur-Seiche is certainly longer, as only the direct route (as the crow flies) between Dinard and Vern-sur-Seiche has been calculated here.
Air line (approximately)
74 kilometers
40 nautical miles