第5周项目1-三角形类雏形

#include<iostream>
#include<cstdlib>
#include<Cmath>
using namespace std;
class Triangle
{
public:
void setABC(double x, double y, double z);
double perimeter();
double area();
private:
double a,b,c;
};
int main()
{
Triangle tri1;
tri1.setABC(4,5,6);
cout<<"三角形的周长为："<< tri1.perimeter()<<'\t'<<"面积为："<< tri1.area()<<endl;
return 0;
}

void Triangle::setABC(double x, double y, double z)
{
if(x+y>z&&x+z>y&&y+z>x)
{
a=x;
b=y;
c=z;
}
else
{
cout<<"不能构成三角形"<<endl;
exit(0);
}
}

double Triangle::perimeter(void)
{
return a+b+c;
}

double Triangle::area(void)
{
double p=(a+b+c)/2;
return sqrt(p*(p-a)*(p-b)*(p-c));
}
<img src="http://img.blog.csdn.net/20160331090643722" alt="" />