That's interesting. This sentence is also unnatural in English. A city can be sprawling, vast, or big. A room, car, or any sort of living quarters would be spacious or roomy. Streets can be wide but I wouldn't really describe them as spacious.
If a city is "spacious", does it mean that the city is big, or just that there is a lot of space between the buildings? I wonder what the course contributors were thinking.
"Spacious" can, you are right to say, mean "covering much space", hence simply "expansive", and it can also be used to talk about something that affords large amounts of space.
But in the context of everyday use, it is now very rarely used in the first way. if I say "Leeds is a spacious city" I must mean something along the lines of "Leeds has many parks", "Leeds has wide roads", "Leeds is not overcrowded". And a brief google shows that the phrase is often used in published works in this way. To take just one example:
"It is a spacious city with an excellent infrastructure of wide boulevards..."
Meanwhile, we do find the first usage, but much earlier, e.g. in a letter from Defoe:
"York, as I have said, is a spacious city, it stands upon a great deal of ground, perhaps more than any city in England out of Middlesex, except Norwich..."
I think waasi3a should be translated as "vast" - rather than "spacious" - in the case of cities or countries or other vast open spaces.
"Spacious", in English appears more appropriate to smaller enclosed quarters, like a car or a house. - A university, which covers vast campus grounds, is not spacious. Its mensa or its auditorium or its dormitories may be spacious, but not the university as a whole institution.