#include<iostream> using namespace std; int main() { float r1=1,r3=3,r5=5,r7=7,r9=9; cout<<3.1415926*r1*r1<<endl; cout<<3.1415926*r3*r3<<endl; cout<<3.1415926*r5*r5<<endl; cout<<3.1415926*r7*r7<<endl; cout<<3.1415926*r9*r9<<endl; }