                    
1.                                                    1  2           1                    
                                                       
2.      
                 1 2       90                                     1    90   2                          2                       2           
                                       
    
                
3.         
                                                 
4.         
                     1 2      90             1       45                                          
         1    90                          2    45       
                             
5.      
                      1  2              4              
               
                            
6.         
                             
                  
7.           
                                
8.      
                                                         
9.         
                                                                                               
                                 
                                                                                                                                    
                                                           