... p1,phanso p2) { phanso p;p.tu=p1.tu *p2. mau-p1.mau *p2. tu;p.mau=p1.mau *p2. mau;return rutgon(p);}phanso cong(phanso p1,phanso p2) {phanso p;p.tu =p2. mau*p1.tu+p1.mau *p2. tu;p.mau=p1.mau *p2. mau;return ... a,b,c,p;a=d1.dodai(d2);b=d2.dodai(d3);c=d3.dodai(d1);p=(a+b+c)/2;return sqrt(p*(p-a)*(p-b)*(p-c));}double chuvi(diem d1,diem d2,diem d3){double a,b,c;a=d1.dodai(d2);b=d2.dodai(d3);c=d3.dodai(d1);return ... diem::in(){ - 4 - Trường Cao Đẳng Bách Khoa Hưng Yên CĐ 5.2 - K3 - CNTTcout<<"\n \t"<<x<<setw(5)<<y;}double diem::dodai(diem d){return sqrt(pow(x-d.x,2)+pow(y-d.y,2));}double...