Is the word acha the same in Brazilian and European Portuguese?

Yes.

The word "acha" is identical in meaning, spelling, and grammatical conjugation in both Brazilian and Continental Portuguese. It is the third-person singular form of the verb achar (to find/to think). The primary difference is pronunciation: Brazilian Portuguese typically features more open vowels, whereas Continental Portuguese tends to use more closed or reduced vowels, making the unstressed "a" at the end of the word sound much more subtle or nearly neutralized in Portugal. While a Portuguese person might change the subject of the sentence (using tu achas instead of vocio acha for informal "you"), the word "acha" itself remains the same when referring to the third person or formal address.

Brazilian Portuguese Examples

1. Você acha que vai chover? (Do you think it is going to rain?)
2. Ela acha o filme muito bom. (She thinks the movie is very good.)
3. O que você acha desse cara? (What do you think of this guy?)
4. Ele acha que o carro é velho. (He thinks the car is old.)
5. Você acha que ele está mentindo? (Do you think he is lying?)

Continental Portuguese Examples

1. Acha que vai chover? (Do you think it is going to rain?)
2. Ela acha o filme muito bom. (She thinks the movie is very good.)
3. O que é que acha deste rapaz? (What do you think of this guy?)
4. Ele acha que o carro é velho. (He thinks the car is old.)
5. Acha que ele está a mentir? (Do you think he is lying?)