Turbo C++ program to find area of a circle

#include<iostream.h>
#include<conio.h>
double ar(float);
int main()
{
 clrscr();
 int r;
 double area;
 cout<<"Enter the radius";
 cin>>r;
 area=ar(r);
 cout<<"Area = "<<area;
 getch();
 return 0;
}
double ar(float r)
{
 double area;
 area=3.14*r*r;
 return area;
}