代码:
#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);
double Distance(CPoint p) const; //两点之间的距离(一点是当前点——想到this了吗?另一点为p)
void input(); //以x,y 形式输入坐标点
void output(); //以(x,y) 形式输出坐标点
};
class CTriangle
{
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);
float perimeter(void);//计算三角形的周长
float area(void);//计算并返回三角形的面积
bool isTriangle();//判断是否为三角形
bool isRightTriangle(); //是否为直角三角形
bool isIsoscelesTriangle(); //是否为等腰三角形
private:
CPoint A,B,C; //三顶点
};
CPoint::CPoint(double xx,double yy)
{
x=xx;
y=yy;
}
double CPoint::Distance (CPoint p) const
{
double d;
return d=sqrt((p.x-x)*(p.x-x)+(p.y-y)*(p.y-y));
}
void CPoint::input()
{
cin>>x>>y;
}
void CPoint::output()
{
cout<<"("<<x<<","<<y<<")"<<endl;
}
void CTriangle::setTriangle(CPoint &X,CPoint &Y,CPoint &Z)
{
A=X;
B=Y;
C=Z;
}
float CTriangle::perimeter(void)
{
float c;
return c=A.Distance(B)+A.Distance(C)+B.Distance(C);
}
float CTriangle::area(void)
{
float s,p;
p=(A.Distance(B)+A.Distance(C)+B.Distance(C))/2;
return s=sqrt(p*(p-A.Distance(B))*(p-A.Distance(C))*(p-B.Distance(C)));
}
bool CTriangle::isTriangle()
{
double a=B.Distance(C),b=A.Distance(C),c=A.Distance(B);
if(a+b>c&&a+c>b&&b+c>a)
return true;
else
return false;
}
bool CTriangle::isRightTriangle()
{
double a=B.Distance(C),b=A.Distance(C),c=A.Distance(B);
if(a*a+b*b==c*c||b*b+c*c==a*a||a*a+c*c==b*b)
return true;
else
return false;
}
bool CTriangle::isIsoscelesTriangle()
{
double a=B.Distance(C),b=A.Distance(C),c=A.Distance(B);
if(a==b||a==c||b==c)
return true;
else
return false;
}
int main()
{
CPoint p1,p2,p3;
cout<<"请输入第一个点的坐标:";
p1.input();
cout<<"请输入第二个点的坐标:";
p2.input();
cout<<"请输入第三个点的坐标:";
p3.input();
CTriangle T(p1,p2,p3);
if(T.isTriangle())
{
cout<<"这三个点可以构成三角形"<<endl;
cout<<"该三角形的周长为:"<<T.perimeter()<<endl;
cout<<"该三角形的面积为:"<<T.area()<<endl;
if(T.isRightTriangle())
{
cout<<"该三角形是直角三角形"<<endl;
}
else
cout<<"该三角形不是直角三角形"<<endl;
if(T.isIsoscelesTriangle())
{
cout<<"该三角形是等腰三角形"<<endl;
}
else
cout<<"该三角形不是等腰三角形"<<endl;
}
else
cout<<"这三个点不能构成三角形"<<endl;
return 0;
}
运行结果:
![](https://img.laitimes.com/img/__Qf2AjLwojIjJCLyojI0JCLiIXZ05WZD9CX5RXa2Fmcn9CXwczLcVmds92czlGZvwVP9EUTDZ0aRJkSwk0LcxGbpZ2LcBDM08CXlpXazRnbvZ2LcRlMMVDT2EWNvwFdu9mZvwlNOhkYrJlMZZXUYpVd1kmYr50MZV3YyI2cKJDT29GRjBjUIF2LcRHelR3LcJzLctmch1mclRXY39DMxkDO0gTN2ETMxQDM1EDMy8CX0Vmbu4GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.jpg)