Has any one got any idea why this doesn;t work!!

Code:

//Program to find circle values.
#include <iostream>
using namespace std;
int main()
{
float radius;
float pi;
pi = 3.14;
float r2;
r2 = radius*radius;
float area;
area = pi*r2;
{
cout << "Please input a radius so that I can work out the area of the circle!\n";
cin >> radius;
cout << "Thankyou! Your answer is below:\n";
cout << "you entered:" << radius;
cout << "/ncurrent status: not working";
//the above line is a debugging tool
}
return 0;
}