
class Maths{ |
double r; |
double girth; |
double area; |
final double PI=3.14; |
public void setR(double r) { |
this.r=r; |
} |
public double getR() { |
return r; |
} |
public void girth() { |
girth=2*PI*r; |
System.out.println("这个圆的周长是:"+girth); |
} |
public void area() { |
area=PI*r*r; |
System.out.println("这个圆的面积是:"+area); |
} |
} |
public class Main { |
public static void main(String[] args){ |
Maths maths=new Maths(); |
maths.setR(5.66); |
maths.girth(); |
maths.area(); |
|
} |
} |



