Ho aspettato l'autobus per un quarto d'ora sotto la pioggia.
I waited for the bus for a quarter of an hour in the rain.
Ci vuole solo un quarto d'ora per arrivare a casa mia.
It only takes a quarter of an hour to get to my house.
Tra un quarto d'ora saremo già alla stazione.
In a quarter of an hour we will already be at the station.
Note
The article is part of the word: il quarto d'ora. That way you learn the gender with it.
Remember il quarto d'ora for good. ripiti brings the word back just before you forget it, with these sentences. Free, no account needed, works offline.