Hello!! i need your help! this is my code, it not so good as i wander - it is not working. i have not idea anymore.

</code>// need to get next parameter
static double getParametr(){
       Scanner scanner = new Scanner(System.in);
        param = scanner.nextDouble();
        return param;
}
..........
................
if (i==1){
                System.out.println("vvedite storoni pryamougolnika:  ");
                Shape parA = new Rectangle();
                parA.a = Shape.getParametr(); --- this is ok
                double aa = parA.a;
                Shape parB = new Rectangle();
                parB.b = Shape.getParametr();  ------ this is no work!!! 
                double bb = parB.b;
                Rectangle rec = new Rectangle(aa, bb);
                arrayFigur[i] = rec.area();
            }

how fix mistake?