第四周项目1.2

#include <iostream>#include <cmath>using namespace std;class Triangle{public:    Triangle():a(1),b(1),c(1){};    double perimeter();//计算三角形的周长    double area();//计算并返回三角形的面积    void showMessage();private:    double a,b,c;//三边为私有数据成员};void Triangle::showMessage(){    cout<<"三角形的三边长分别为: "<<a<<' '<<b<<' '<<c<<endl;    cout<<"该三角形的周长为"<<perimeter()<<",面积为: "<<area()<<endl;}double Triangle::perimeter(){    return a+b+c;}double Triangle::area(){    double p=(a+b+c)/2;    return sqrt(p*(p-a)*(p-b)*(p-c));}int main(){    Triangle Tri;    Tri.showMessage();    return 0;}