The calculated distance (air line) between Zürich (Kreis 5) / Gewerbeschule and Riehen is approximately 43 miles respectively 70 kilometers.
By car or train, the actual journey to Riehen is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 5) / Gewerbeschule and Riehen has been calculated here.
Air line (approximately)
70 kilometers
38 nautical miles