第五周任务一（4）

 

 

#include <iostream>#include<cmath>using  namespace std;class Triangle{public: Triangle();//此句一定要有 Triangle(float x,float y ,float z ):a(x),b(y),c(z){} float Perimeter(void); float Area(void); void ShowMessage();private: float a,b,c;};Triangle::Triangle(){ a=1; b=1; c=1;}void Triangle::ShowMessage(){ cout<<"三角形的三边长分别为："<<a<<'\t'<<b<<'\t'<<c<<endl; cout<<"该三角形的周长为："<<Perimeter()<<'\t'<<"面积为："<<Area()<<endl; //函数名前不用再加T1,因为主函数中已经有了。}void main(void){ Triangle T1; T1.ShowMessage();    Triangle T2(3,4,5); T2.ShowMessage();}float Triangle::Perimeter(void){ float l; l=a+b+c; return l;}float Triangle::Area(void){ float p,m; m=(a+b+c)/2; p=sqrt(m*(m-a)*(m-b)*(m-c)); return p;}