C++1.2，1.3

#include<iostream>

using namespace std;

int main(){

  int a,b,l,s;

  a=10;b=20;

  l=2*(a+b); s=a*b;

  cout<<"L="<<l<<endl;

  cout<<"S ="<<s<<endl;

  system("pause");

  return 0; 

} 

#define pi 3.14159

#include<iostream>

using namespace std;

int main(){

  int r=10;

  float l,s;

  l=2*pi*r; s=pi*r*r;

  cout<<"L="<<l<<endl;

  cout<<"S="<<s<<endl;

return 0;

}