Learn Farsi: شمشیرها با این روش در کارگاه شکل داده می‌شدند. - Swords used to be shaped in the workshop with this method.

It uses the past participle of the main verb plus the past continuous form of شدن (to become). The main verb is شکل دادن (to shape). Its past participle is شکل داده. Then we add می‌شدند to match the plural subject شمشیرها (swords).

Why is the noun شکل (shape) included in the passive verb structure?

The verb 'to shape' in Farsi is a compound verb: شکل دادن (literally 'to give shape'). When making a passive compound verb, the non-verbal part (شکل) stays exactly as it is, and only the verbal part (دادن) changes into the past participle (داده).

Does the verb tense here mean 'used to be shaped' or 'were being shaped'?

It can mean both! The Farsi past continuous tense with the می prefix covers both ongoing actions in the past ('were being shaped at that exact moment') and habitual actions in the past ('used to be shaped in general'). The context of describing a method usually implies a habitual action here.

The word با means 'with', but does it mean 'along with' or 'using' in this sentence?

Here, با means 'using' or 'by means of', pointing to the technique used. While با can also mean 'together with' (like going to a workshop with a friend), in با این روش it introduces the method used to do the action.