求大佬支援问题在哪？
package C3;

class Circle {
private static double PI=3.142;
static double r;

public Circle() {
}

public Circle(double R) {
r = R;
}

public double getAear() {
return PI * r * r;
}

public double getLength() {
return PI * r * 2;
}

public double getR() {
return r;
}

public void setR(double R) {
r = R;
}
}
public class C3{
public static void main(String[] args) {
Circle C1=new Circle();
C1 .r=C1.Circle(2);
System.out.println("周长："+C1.getLength()+"面积："+C1.getAear());
}
}