C++题《设计三角形类求边长与面积》

Question

设计一个名为TriAngle的三角形类，其属性为三角形的三个顶点，并能够计算三角形的三条边长与面积。
写一个main函数进行调试。

Answer 1

#include <iostream>
#include <cmath>
using namespace std;
class TriAngle
{
public:
TriAngle(float a,float b,float c,float d,float e,float f);
void length(float &a,float &b,float &c);
float square();
private:
struct point{
float x;
float y;
};
point A,B,C;
};
TriAngle::TriAngle(float a,float b,float c,float d,float e,float f)
{
A.x=a,A.y=b;
B.x=c,B.y=d;
C.x=e,C.y=f;
}
void TriAngle::length(float &a,float &b,float &c)
{
a=sqrt((A.x-B.x)*(A.x-B.x)+(A.y-B.y)*(A.y-B.y));
b=sqrt((A.x-C.x)*(A.x-C.x)+(A.y-C.y)*(A.y-C.y));
c=sqrt((C.x-B.x)*(C.x-B.x)+(C.y-B.y)*(C.y-B.y));
}
float TriAngle::square()
{
float a,b,c;
length(a,b,c);
float p=(a+b+c)/2;
return sqrt(p*(p-a)*(p-b)*(p-c));
}
int main()
{
float x1,y1,x2,y2,x3,y3;
float leng1,leng2,leng3; //三边长
cout << "分别输入三个点的坐标:" << endl;
cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
TriAngle triangle(x1,y1,x2,y2,x3,y3);
triangle.length(leng1,leng2,leng3);
cout << "边长分别是:" << endl;
cout << leng1 << endl;
cout << leng2 <<endl;
cout << leng3 << endl;
cout << "面积是:" << triangle.square()<< endl;
return 0;
}

Answer 2

#include<iostream.h>
#include<math.h>
class tra
{
public:
tra();
void cacu();
void disp();

double a1,a2,a3,leng,square;

};
tra::tra()
{
cout<<"请输入三角形的边长a:"<<endl;
cin>>a1;
cout<<"请输入三角形的边长a:"<<endl;
cin>>a2;
cout<<"请输入三角形的边长a:"<<endl;
cin>>a3;
leng=a1+a2+a3;
leng=1.0/2*leng;
}

void tra::cacu()
{
square=sqrt((leng-a1)*(leng-a2)*(leng-a3)*leng);

}
void tra::disp()
{
if(((a1+a2)<=a3)||((a2+a3)<=a1)||((a1+a3)<=a2)) cout<<"您输入的三连构不成三角形！"<<endl;
else cout<<"三角形面积为："<<square<<endl;
}
void main()
{
tra obj;
obj.cacu();
obj.disp();
}