//Test.java
import?java.util.Scanner;
public?class?Test?{

	/**
	?*?@param?args
	?*/
	public?static?void?main(String[]?args)?{
		//?TODO?Auto-generated?method?stub
		Scanner?input?=?new?Scanner(System.in);
		System.out.println("pls?input?the?r?of?circle");
		float?r?=?input.nextFloat();
		System.out.println("pls?input?the?length?of?rectangle");
		float?length?=?input.nextFloat();
		System.out.println("pls?input?the?width?of?rectangle");
		float?width?=?input.nextFloat();
		Circle?circle?=?new?Circle(r);
		Rectangle?rectangle?=?new?Rectangle(length,width);
		
		System.out.println("圓形的周長為"?+?circle.perimeter());
		System.out.println("圓形的面積為"?+?circle.square());
		
		System.out.println("長方形的周長為"?+?rectangle.perimeter());
		System.out.println("長方形的面積為"?+?rectangle.square());
	}

}

Shape.java

public?abstract?class?Shape?{
	public?abstract?float?square();
	public?abstract?float?perimeter();
}

Circle.java

public?class?Circle?extends?Shape{
	float?r;
	public?Circle(float?r0){
		r?=?r0;
	}
	
	
	@Override
	public?float?perimeter()?{
		//?TODO?Auto-generated?method?stub
		return?2*r*(float)Math.PI;
	}

	@Override
	public?float?square()?{
		//?TODO?Auto-generated?method?stub
		return?(float)Math.PI*r*r;
	}
}

Rectangle.java

public?class?Rectangle?extends?Shape?{
	public?float?length;
	public?float?width;

	public?Rectangle(float?length0,float?width0){
		width?=?width0;
		length?=?length0;
		if(length?<=?0){
				System.out.println("輸入的長度<=0，有誤");
		}
		
		if(width?<=?0){
				System.out.println("輸入的寬度<=0，請重新輸入");
		}
	}
	@Override
	public?float?perimeter()?{
		//?TODO?Auto-generated?method?stub
		return?2*(length?+?width);
	}

	@Override
	public?float?square()?{
		//?TODO?Auto-generated?method?stub
		return?length?*?width;
	}

}