The calculated distance (air line) between Bellinzona and Zürich (Kreis 3) is approximately 84 miles respectively 135 kilometers.
By car or train, the actual journey to Zürich (Kreis 3) is certainly longer, as only the direct route (as the crow flies) between Bellinzona and Zürich (Kreis 3) has been calculated here.
Air line (approximately)
135 kilometers
73 nautical miles