show that 2D array is an array of arrays

void setup () {
  int [][] show_array = {
    {
      2, 4, 6, 8, 10
    }
    , {
      1, 3, 5, 7, 9
    }
    , {
      1, 2, 3, 4, 5
    }
  };
  int ArrayOfArray = sum_array(show_array[1]);
  println ("Show array 2D is array of array and sum of show_array that index is 1 = "+ArrayOfArray);
}

int sum_array (int [] a) {
  int sum = 0;
  for (int i = 0; i<a.length; i++) {
    sum = sum+a[i];
  }
  return sum;
}