c3-6.cpp

来自「谭浩强C程序设计习题答案」· C++ 代码 · 共 21 行

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
int main()
{
 double a,b,c;
 cout<<"please enter a,b,c:";
 cin>>a>>b>>c;
 if (a+b>c && b+c>a && c+a>b)
  {
   double s,area;
   s=(a+b+c)/2;
   area=sqrt(s*(s-a)*(s-b)*(s-c));
   cout<<setiosflags(ios::fixed)<<setprecision(4);
   cout<<"area="<<area<<endl;
  }
 else cout<<"it is not a trilateral!"<<endl;
 return 0;
}