RazaCercCircumscris

#include <bits/stdc++.h>
using namespace std;
float a, b, c, s, A, radius;

bool Valid(float x, float y, float z)
{
    if(x + y <= z || x + z <= y || y + z <= x)
        return false;
    else
        return true;
}

int main()
{
    cin>>a>>b>>c;
    if(!Valid(a,b,c))
        cout<<"Imposibil";
    else
    {
        s=(a+b+c)/2;
        A = sqrt((s*(s-a)*(s-b)*(s-c)));
        radius=a*b*c/(4*A);
        cout<<setprecision(2)<<fixed<< (int)(radius*100)/100.0;
    }
    return 0;
}