Tam giác

#include <iostream>
using namespace std;
enum thuoctinh
{
	CAN, DEU, VUONGCAN, VUONG, THUONG
};
struct diem
{
	float x, y;
};
struct tamgiac
{
	diem A, B, C;
};
void nhap(diem &d)
{
	cout << "Nhap hoanh do = ";
	cin >> d.x;
	cout << "Nhap tung do = ";
	cin >> d.y;
}
void xuat(diem d)
{
	cout << "(" << d.x << ";" << d.y << ")" << endl;
}
double khoangcach(diem a, diem b)
{
	return sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2));
}
int kiemtra(tamgiac ABC)
{
	double a = khoangcach(ABC.A, ABC.B);
	double b = khoangcach(ABC.B, ABC.C);
	double c = khoangcach(ABC.C, ABC.A);
	if (a + b > c || a + c > b || b + c > a)
	{
		if (a == b || b == c || a == c)
		{
			if (a == b && a == c) return DEU;
			else
			{
				if (a * a + b * b == c * c || a * a + c * c == b * b || c * c + b * b == a * a) return VUONGCAN;
				else return CAN;
			}
		}
		if (a * a + b * b == c * c || a * a + c * c == b * b || c * c + b * b == a * a) return VUONG;
		else return THUONG;
	}
	return -1;
}
int NhapTamGiac(tamgiac &ABC)
{
	nhap(ABC.A);
	nhap(ABC.B);
	nhap(ABC.C);
	int t = kiemtra(ABC);
	if (t == -1) NhapTamGiac(ABC);
	else return t;
}
void ChuViDienTich(tamgiac ABC, double &cv, double &dt)
{
	double a = khoangcach(ABC.A, ABC.B);
	double b = khoangcach(ABC.B, ABC.C);
	double c = khoangcach(ABC.C, ABC.A);
	cout << a << b << c;
	cv = a + b + c;
	dt = sqrt(cv * (cv / 2 - a) * (cv / 2 - b) * (cv / 2 - c) / 2);
}
void main()
{
	tamgiac ABC;
	int t;
	double cv = 0, dt = 0;
	t = NhapTamGiac(ABC);
	switch (t)
	{
	case THUONG:
		cout << "Tam giac thuong\n";
		break;
	case CAN:
		cout << "Tam giac can\n";
		break;
	case VUONGCAN:
		cout << "Tam giac vuong can\n";
		break;
	case VUONG:
		cout << "Tam giac vuong\n";
		break;
	case DEU:
		cout << "Tam giac deu\n";
		break;
	}
	ChuViDienTich(ABC, cv, dt);
	cout << "Chu vi: " << cv << "\nDien tich: " << dt;
}