第四周项目一三角形类的构造函数-3

int main(){
    Triangle Tri1;   //定义边长为1 1 1的三角形类实例
    Tri1.showMessage();
    Triangle Tri2(1.5);//定义边长为1.5 1 1的三角形类实例
    Tri2.showMessage();
    Triangle Tri3(1.5,1.5);//定义边长为1.5 1.5 1的三角形类实例
    Tri3.showMessage();
    Triangle Tri4(7,8,9); //定义边长为7 8 9的三角形类实例
    Tri4.showMessage();
    return 0;
}

#include <iostream>#include <cmath>using namespace std;class Triangle{public:    double perimeter();    double area();    void showMessage();    Triangle(double x,double y,double z)    {        a=x;        b=y;        c=z;    }private:    double a,b,c;};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<<endl;}double Triangle::perimeter(){    return a+b+c;}double Triangle::area(){    double p,s;    p=(a+b+c)/2;    s=sqrt(p*(p-a)*(p-b)*(p-c));    return s;}int main(){    Triangle Tri1(1,1,1);    Tri1.showMessage();    Triangle Tri2(1.5,1,1);    Tri2.showMessage();    Triangle Tri3(1.5,1.5,1);    Tri3.showMessage();    Triangle Tri4(7,8,9);    Tri4.showMessage();    return 0;}

运行结果：

<img src="http://img.blog.csdn.net/20150401200100334?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvenM5NTI4/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />