Помогите написать программку c++

//формулы сам(а) добавишь в программку
include lt;iostreamgt;
include lt;cmathgt;
using namespace std;
int main()

 int choose = 0;
int a, b, alpha, beta, formula, basis, height, square;
cout lt;lt; "Input your number(1-3):" lt;lt; endl;
cout lt;lt; "1.Enter two parties of a triangle and a corner between them:" lt;lt; endl;
cout lt;lt; "2.Enter parties of a triangle and two corners:" lt;lt; endl;
cout lt;lt; "3.Enter basis and height:" lt;lt; endl;
 cin gt;gt; choose;
switch (choose)
 

  case 1:
  cin gt;gt; a gt;gt; b gt;gt; alpha;
  //formula =
  cout lt;lt; "formula = " lt;lt; formula;
  cout lt;lt; endl;

 case 2:
     cin gt;gt; a gt;gt; beta gt;gt; alpha;
   //formula =
   cout lt;lt; "formula = " lt;lt; formula;
   cout lt;lt; endl;

  case 3:
     cin gt;gt; basis gt;gt; height;
   //square = 
  cout lt;lt; "square = " lt;lt; square;
  cout lt;lt; endl;

 default:
  cout lt;lt; "Wrong number!";
 
return 0;