Давид 2 задача

#include<iostream>
#include<cmath>

using namespace std;

const double pi = 3.14;

double sectorArea(double R, double a){
    return (pi*pow(R,2)*a)/360;
}

int main()
{
    double R, a, b, c;
    cin >> R >> a >> b >> c;
    cout << sectorArea(R,  a) << endl;
    cout << sectorArea(R,  b) << endl;
    cout << sectorArea(R,  c);
}