Area and Circumference of circle in C++

#include<iostream>

#include<cmath>

using namespace std;

const float pi = 3.14;

class circle{

    public: float area(int r){

        return pi * pow(r,2);

    }

    

    float circumference(int r){

        return 2 * pi * r;

    }

};

int main(){

    int r;

    cout << "Get Area and Circumference of circle:\n";

    cout << "enter radius of circle: ";

    cin>>r;

    

    circle c;

    cout<<"area: "<<c.area(r)<<"\n";

    cout<<"circumference: "<<c.circumference(r)<<"\n";

    

}