编辑代码

public class lsy {
    public static void main(String[] args){
        double m = 2;//长
        double n = 3;//宽
        double zc = 2*m+2*n;
        double mj = m*n; 
        System.out.println("周长为"+zc);
        System.out.println("面积为"+mj);
    }
}