#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max ()\min() using namespace std; int main(){ doudle pai=3.141592; int r1=1,r2=3,r3=5,r4=7,r5=9 cout<<pai*r1*r1<<endl; cout<<pai*r2*r2<<endl; cout<<pai*r3*r3<<endl; cout<<pai*r4*r4<<endl; cout<<pai*r5*r5<<endl; return 0; }