Explicație:
#include <iostream>
#include <cmath>
#include <iomanip>
#define pi 3.14159265
using namespace std;
int main()
{
double a, b, u;
cin >> a >> b >> u;
double c = sqrt ( a * a + b * b - 2 * a * b * cos ( pi * u / 180 ) ) ;
cout << std::fixed << std::setprecision(2) << c;
return 0;
}
