Сложит 2с, с. 1100101+1001011 1010110+1011108с, с. 2675+3563. 4365+544516 с, с. 1235AB+4532FC 6742BC+3254AF Вычитат2с, с. 1101011-110110. 1011011-1011018с, с 4567-2674. 5674-436516с, с 4532FC-1235AB 6742BC-3254AF​

#include <iostream>
#include <iomanip
#include <cmath>
using namespace std;

double St(double x1, double y1, double x2, double y2)
{
return sqrt((y2-y1)*(y2-y1)+(x2-x1)*(x2-x1));
}

double Per(double a, double b, double c)
{
return a+b+c;
}

double S(double a, double b, double c)
{
double p2 = Per(a,b,c)/2;
return sqrt(p2*(p2-a)*(p2-b)*(p2-c));
}

int main()
{
    double x1, y1, x2, y2, x3, y3;
    double a, b, c, p, s;
    cin >> x1 >> y1;
    cin >> x2 >> y2;
    cin >> x3 >> y3;
    a = St(x1,y1,x2,y2);
    b = St(x1,y1,x3,y3);
    c = St(x2,y2,x3,y3);
    p = Per(a,b,c);
    s = S(a,b,c);
    cout.setf(std::ios::fixed);
    cout.precision(6);
    cout << "p = " << p << "\n";
    cout << "s = " << s << "\n";
    system("Pause");
    return 0;
}

Пример:
1 1
4 1
1 5
p = 12.000000
s = 6.000000