Brazilian culture question ?

My son and i have a curiosity about brazilians.My son wonders if they are considered to be spanish or latin . I say No because they speak Portuguese.But If a Brazilian person was to fill out a census report how do they identify ? I mean there is no box for Brazilian . I am Bi racial Sicilian american and black american and there is no biracial box or multiracial or multicultural box so i pick other.