I know that commonly, the roman numerals are used to refer to a date or, more precisely, to a specific century, like in the examples below:
- Aconteceu no século XX;
- Um dos livros mais importantes do século XVIII;
I'd like to know if there is some rule to use this type of number in portuguese. Should they just be used to talk about a century or is this just a convention?
Can I use it to say something like "Eu tenho X anos" or not?