编写一个Shape类，具有属性：周长和面积；

定义其子类三角形和矩形，分别具有求周长的方法。

定义主类E，在其main方法中创建三角形和矩形类的对象，

并赋给Shape类的对象a、b，使用对象a、b来测试其特性。

package T092208;public class Shape {    private int bian;    private double zhouchang;    private double mianji;    public int getBian() {        return bian;    }    public void setBian(int bian) {        this.bian = bian;    }    public double getZhouchang() {        return zhouchang;    }    public void setZhouchang(double zhouchang) {        this.zhouchang = zhouchang;    }    public double getMianji() {        return mianji;    }    public void setMianji(double mianji) {        this.mianji = mianji;    }    public void bian(){        System.out.println("您创建了一个"+bian+"边形！");    }}package T092208;public class San extends Shape {    double[] bianchang=new double[3];    San(){            }    San(double a,double b, double c){        bianchang[0]=a;        bianchang[1]=b;        bianchang[2]=c;    }    public void zhouchang(){        if(getBian()==3&&bianchang[0]+bianchang[1]>bianchang[2]&&bianchang[0]-bianchang[1]