第五周任务1-3

#include <iostream>#include <cmath>using namespace std;class Triangle{public:float perimeter(void);float area(void);void showMessage();Triangle(float x=1,float y=2,float z=2);private:float a,b,c;};void main(){Triangle Tri1;Tri1.showMessage();}float Triangle::perimeter(void){return (a+b+c);}float Triangle::area(void){float s,m;s=(a+b+c)/2;m=sqrt(s*(s-a)*(s-b)*(s-c));return m;}void Triangle::showMessage(){cout<<"三角形的三边为： "<<a<<'\t'<<b<<'\t'<<c<<endl;cout<<"该三角形的周长为："<<perimeter()<<'\t'<<"面积为："<<area()<<endl;}Triangle::Triangle(float x,float y,float z){a=x;b=y;c=z;}