The calculated distance (air line) between Therwil and Zürich (Kreis 3) is approximately 45 miles respectively 73 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 Therwil and Zürich (Kreis 3) has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles