Matrix in C

matrix.c

void matrix() {
  char mtx[2][3] = {{"mat"}, {"rix"}};
  mtx[1][1] = '1';
  for (int i = 0; i < 2; i++) {
    printf("%i)idx: [%c] [%c] [%c]\n", i, mtx[i][0], mtx[i][1], mtx[i][2]);
  }
  printf("\tsizeof arr = %i bytes\n", sizeof(mtx));
}