張凱婷

1. #include<iostream>
   
2. #include<cstdlib>
   
3. using namespace std;
   
4. int main()
   
5. {
   
6.     float num,numl;
   
7.     cout<<"輸入圓的半徑:";
   
8.     cin>>num;
   
9.    
   
10.     cout<<num*num*3.14;
    
11.     system("pause");
    
12.     return 0;
    
13. }

複製代碼