求大佬们指点一下，有哪些地方错了我实在找不到了#includ

求大佬们指点一下，有哪些地方错了我实在找不到了
#include<iostream>
using namespace std;
class yuan
{private:
float r;
public:
clud(float m);
float square();
float circum();
};
yuan::clud(float m)
{
r=m;
}
float yuan::square()
{
return(r*r*3.14);
}
float yuan::circum()
{
return(2*3.14*r);
}
float main()
{
yuan f(15.0);
cout<<"周长"<<f.circum()<<"面积"<<f.square()<<endl;
return 0;
}