一个关于Java面向对象的程序设计题，求解

Question

如题所述

Answer 1

import java.util.Scanner;
public class Demo{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
Square s = new Square();
System.out.println("请输入一个正方形的边长");
double d =input.nextDouble();
s.perimeter(d);
s.area(d);
}
}
class Square implements Shape{//正方形类
public void perimeter(double d) {
double p =4*d;
System.out.println("该正方形的周长为："+p);
}
public void area(double d) {
double s = d*d;
System.out.println("该正方形的面积为："+s);
}
}
interface Shape{//接口
public void perimeter(double d);//周长
public void area(double d);//面积
}