java第八次作业

 
public class Shape {
	final static double PI=3.1415926;
	void  s1(int r){
		 double s1=r*r*PI;
		 System.out.println("圆形面积："+s1);
		}
		 void s2(int a,int b){
		  float s2=a*b;
		  System.out.println("矩形面积："+s2);
		 }
		 
		 class shap{
		}public class shap1 extends Shape {
		 
		 public static void main(String[] args) {
		  Shape a=new Shape();
		  a.s1(2);
		  a.s2(1, 11);
		  
		 
	}
 
}}