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

Yes

The word "cerca" is identical in both Brazilian and Continental Portuguese in terms of spelling, meaning, and grammatical function. It can function as a noun (referring to a fence or an enclosure) or as part of the prepositional phrase "cerca de" (meaning approximately or about). The only distinction between the two dialects lies in pronunciation (phonology), specifically regarding vowel tension and the articulation of unstressed syllables.

Brazilian Portuguese Examples

1. O cachorro pulou a cerca. (The dog jumped the fence.)
2. Eles moram a cerca de dois quilômetros daqui. (They live about two kilometers from here.)
3. A cerca de madeira precisa de pintura. (The wooden fence needs painting.)
4. Tem cerca de cem pessoas na festa. (There are about one hundred people at the party.)
5. O fazendeiro construiu uma cerca nova. (The farmer built a new fence.)

Portuguese (Portugal) Examples

1. O cão saltou a vedação. (The dog jumped the fence.)
2. Eles vivem a cerca de dois quilómetros daqui. (They live about two kilometers from here.)
3. A cerca de madeira precisa de pintura. (The wooden fence needs painting.)
4. Há cerca de cem pessoas na festa. (There are about one hundred people at the party.)
5. O agricultor construiu uma vedação nova. (The farmer built a new fence.)