编写程序，定义一个接口Compute，声明计算周长calgirth（）和面积calarea ()的方法，然后定义一个长方形类RRect和圆类Circle，两个类都实现接口Compute，最后编写测试类进行测试。

interface Compute{
    double PI=3.141592654;
    double calGrith();
    double calArea();
}
class Rect implements Compute{
    private double length;
    private double width;
    
    public Rect(double length,double width) {
        this.length=length;
        this.width=width;
    }
    public double calGrith() {
        return (length+width)*2;
    }

    public double calArea() {
        return length*width;
    }
    
}
class Circle implements Compute{
    private double radius;
    
    public Circle(double radius) {
        this.radius=radius;
    }
    
    public double calGrith() {
        return 2*PI*radius;
    }

    public double calArea() {
        return PI*radius*radius;
    }
}

public class Test {
    public static void main(String[] args) {
        Rect rect=new Rect(2,4);
        System.out.println("rect.calGrith()="+rect.calGrith());
        System.out.println("rect.calArea()="+rect.calArea());
        System.out.println();
        Circle circle=new Circle(1);
        System.out.println("circle.calGrith()="+circle.calGrith());
        System.out.println("circle.calArea()="+circle.calArea());
    }
}