#include <iostream>
#include <cmath>
using namespace std;
class Triangle
{
public:
void showMessage();
Triangle (double x=1,double y=1,double z=1):a(x),b(y),c(z){} //重点 a(x),b(y),c(z){} 实参(形参)
double perimeter(void );
double area(void);
private:
double a,b,c;
};
double Triangle::perimeter(void)
{
double l;
l=a+b+c;
return l;
}
double Triangle:: area(void)
{
double p,s;
p=(a+b+c)/2;
s=sqrt(p*(p-a)*(p-b)*(p-c));
return s;
void Triangle::showMessage()
{
cout<<"该三角形的三条边为:"<<'\t'<<a<<'\t'<<b<<'\t'<<c<<endl;
cout<<" "<<endl;
cout<<"该三角形的周长为:"<<perimeter()&l