#include <bits/stdc++.h>

using namespace std;

int main(){
    double U, D, H, slope, area, perimeter;
    cin >> U >> D >> H;
    area = (U + D) * H / 2;
    slope = hypot((D - U) / 2, H);
    perimeter = U + D + 2 * slope;
    cout << fixed << setprecision(2) << area << endl;
    cout << fixed << setprecision(2) << perimeter << endl;
    return 0;
}