AREA OF CIRCLE WHEN RADIUS IS DOUBLED

#include<iostream.h>
#include<conio.h>
void main()
{
clrscr();
float r,a,A,ratio;
cout<<" enter radius ";
cin>>r;
a=3.14*r*r;
A=3.14*2*r*2*r;
cout<<" area of circle is:: "<<a<<"\n";
cout<<" area of circle when radius is doubled:: "<<A<<"\n";
ratio=a/A;
cout<<" The Ratio Of Areas Of the Two Circles is:: "<<ratio;
getch();
}