how to create option at the time of using areas?

c ++ I did areas of these. I want to Use FUNCTIONS to find the areas of different geometrical figures. This has 4 options that can be chosen by the user. The 4 options are – a) Area of a circle b) Area of a rectangle c) Area of a triangle d) Area of a square

  #include<iostream>
using namespace std;
int area(int);
int area(int ,int);
float area(float);
float area(float ,float);
int main()
{
        int s ,l ,c;
        float r ,b ,h;
        cout <<"Enter radius of circle:";
        cin >>r;
        cout<<"Enter length and breadth of rectangle:";
        cin>>l>>c;
        cout<<"Enter base and height of triangle:";
        cin>>b>>h;
        cout<<"Enter side of a square:";
        cin>>s;
        cout<<endl;

    cout<<"Area of circle: "<<area(r)<<endl;
    cout<<"Area of rectangle: "<<area(l,c)<<endl;
    cout<<"Area of triangle: "<<area(b,h)<<endl;
    cout<<"Area of square: "<<area(s)<<endl;
}
int area(int s)
{
    return(s*s);
}
int area(int l,int c)
{
    return(l*c);
}
float area(float r)
{
    return(3.14*r*r);
}
float area(float b,float h)
{
   return((b*h)/2);
}