创建一个关于三角形的类

#include<iostream>
#include<math.h>
using namespace std;
class Triangle
{
public:
void setABC(double x,double y,double z);
double perimeter();
double area();
private:
double a,b,c;

};
void Triangle::setABC(double x,double y,double z)
{
a=x;b=y;c=z;
}
double Triangle::perimeter()
{

return a+b+c;
}

double Triangle::area()
{
double x;
x=(a*a+b*b-c*c)/(2*b);
return 0.5*b*sqrt(a*a-x*x);

}
int main()
{

Triangle tril;
tril.setABC(4,5,6);
cout<<"三角形的周长是："<<tril.perimeter()<<endl;
cout<<"三角形的面积是："<<tril.area()<<endl;
return 0;
}