#include<iostream>
#include<cmath>
using namespace std;
class CPoint
{
private:
double x; // 横坐标
double y; // 纵坐标
public:
CPoint(double xx=0,double yy=0):x(xx),y(yy){}
double Distance(CPoint p) const; // 两点之间的距离(一点是当前点,另一点为参数p)
void input()
{
cin>>x>>y;
} //以x,y 形式输入坐标点
};
double CPoint::Distance(CPoint p) const
{
return sqrt((x-p.x)*(x-p.x)+(y-p.y)*(y-p.y));
}
class CTriangle
{
private:
CPoint A,B,C; //三顶点
double a,b,c; //三边长
public:
CTriangle(CPoint &X,CPoint &Y,CPoint &Z):A(X),B(Y),C(Z){} //给出三点的构造函数
void setTriangle(CPoint &X,CPoint &Y,CPoint &Z)
{
A=X;
B=Y;
C=Z;
}
void setBianChang();
float perimeter(); //计算三角形的周长
float area(); //计算并返回三角形的面积
bool isRightTriangle(); //是否为直角三角形
bool isIsoscelesTriangle(); //是否为等腰三角形
};
void CTriangle::setBianChang()
{
a=A.Distance(B);//分别是AB,BC,AC间距离
b=A.Distance(C);
c=B.Distance(C);
}
float CTriangle::perimeter()
{
return a+b+c;
}
float CTriangle::area()
{
float s,p;
p=(a+b+c)/2;
s=sqrt(p*(p-a)*(p-b)*(p-c));
return s;
}
bool CTriangle::isRightTriangle()
{
if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a)
return true;
return false;
}
bool CTriangle::isIsoscelesTriangle()
{
if(a==b||a==c||b==c)
return true;
return false;
}
int main()
{
CPoint a,b,c;
CTriangle c1(a,b,c);//定义三点后置入三角形三顶点
cout<<"请输入3点坐标:"<<endl;
a.input();
b.input();
c.input();
c1.setTriangle(a,b,c);
c1.setBianChang();
cout<<"三角形周长为:"<<endl;
cout<<c1.perimeter()<<endl;
cout<<"三角形面积为:"<<endl;
cout<<c1.area()<<endl;
if(c1.isIsoscelesTriangle())
cout<<"是等腰三角形。"<<endl;
else
cout<<"不是等腰三角形。"<<endl;
if(c1.isRightTriangle())
cout<<"是直角三角形。"<<endl;
else
cout<<"不是直角三角形。"<<endl;
return 0;
}
运行结果: