归云 · 发布于 2024-11-30 · 浏览 581 回复 0

double r,d,c,s;
cin>>r;
d=r*2;
c=3.1415926*r*2;
s=3.1415926*r*r;
printf("%.4lf %.4lf% .4lf",(double)d,c,s);		
cout<<" ";
return 0;