#include <iostream>
using namespace std;
int main()
{
double r,c,s;
cout<<"请输入圆的半径";
cin>>r;
s=3.14*r*r;
c=3.14*2*r;
cout<<"圆的周长="<<c<<endl;
cout<<"圆的面积="<<s<<endl;
return 0;
}
#include <iostream>
using namespace std;
int main()
{
double r,c,s;
cout<<"请输入圆的半径";
cin>>r;
s=3.14*r*r;
c=3.14*2*r;
cout<<"圆的周长="<<c<<endl;
cout<<"圆的面积="<<s<<endl;
return 0;
}