#include <iostream>
using namespace std;
int main()
{
double r,c,s;
cout<<"請輸入圓的半徑";
cin>>r;
s=3.14*r*r;
c=3.14*2*r;
cout<<"圓的周長="<<c<<endl;
cout<<"圓的面積="<<s<<endl;
return 0;
}
#include <iostream>
using namespace std;
int main()
{
double r,c,s;
cout<<"請輸入圓的半徑";
cin>>r;
s=3.14*r*r;
c=3.14*2*r;
cout<<"圓的周長="<<c<<endl;
cout<<"圓的面積="<<s<<endl;
return 0;
}