Double ab = Math.abs(
                Math.sqrt(
                        Math.pow((B.getX()-A.getX()), 2) +
                                Math.pow((B.getY()-A.getY()), 2)
                )
        );
        Double bc = Math.abs(
                Math.sqrt(
                        Math.pow((C.getX()-B.getX()), 2) +
                                Math.pow((C.getY()-B.getY()), 2)
                )
        );
        Double ca = Math.abs(
                Math.sqrt(
                        Math.pow((A.getX()-C.getX()), 2) +
                                Math.pow((A.getY()-C.getY()), 2)
                )
        );
        return ab + bc + ca;