Can you use US dollars in Rio?

Excuse me, I have a quick question regarding currency usage in Rio de Janeiro. I'm planning a trip there soon and I'm wondering if it's possible to use US dollars directly in the city for purchases like food, accommodations, and entertainment. Are businesses and vendors in Rio accustomed to accepting US dollars as a form of payment, or would it be more practical for me to exchange my dollars for the local currency, the Brazilian Real, before I arrive? Any information you could provide would be greatly appreciated.