没看懂这个报错，怎么改

题目大意是输出两个圆中更大的那个的面积，然后第七行给我了这个报错：'ComparableCircle' 中的 'compareTo(ComparableCircle)' 无法应用于 '()'，但是我实在没发现错哪了

import java.util.Scanner;
public class Main {
    public static void main(String args[]) {
        Scanner in=new Scanner(System.in);
        ComparableCircle a=new ComparableCircle(in.nextDouble());
        ComparableCircle b=new ComparableCircle(in.nextDouble());
        System.out.println(String.format("The max circle's area is %.2f",a.compareTo(b)==1?a.computeArea():b.compareTo()));
    }
}
class Circle{
    double radius;
    Circle(double radius){
        this.radius=radius;
    }
    public double computeArea(){
        return  Math.PI*this.radius+this.radius;
    }
}
class ComparableCircle extends Circle implements Comparable{
    ComparableCircle(double radius){
        super(radius);
    }
    public int compareTo(ComparableCircle o) {
        return this.computeArea()>o.computeArea()?1:0;
    }
}

    System.out.println(String.format("The max circle's area is %.2f",a.compareTo(b)==1?a.computeArea():b.compareTo()));

最后那个b.compareTo()，这个方法里面要传个参数，是a吧