小学数学北师大四年级三角形内角合.docx

 




  
2017.5.25  
    
 
 
   ⑴ 
   180
    
⑵  
    
     

  ⑴ 
        180      
⑵          
⑶              

                        

 
         180     

     
          180         
 
               

 
                         

 
 

      
⒈   
⒉   
⑴⑵⑶……    
①                         2 
②                                   5 
③                                                  5 
④                                      180       8 
⑤                         10 
⑥                            5 
⑦ ①                           
②                    5 

     

      
                 
  

     1.                          
2.                    
3.         
4.                                                     
  
⑴                

⑵             

⑶            



⑴      

⑵      180 

⑶       

