Question

在4*7的格子里有几个长方形包括正方形快！！！！！！！！！！！

Answer 1

正方形 1x1=7x4=28 

            2x2=6x3=18

            3x3=5x2=10

            4x4=4x1=4

       即四种情况（长x宽）相加=60  

  

 长方形 1x2=6x4+3x7=45  ｛ 边长为1x2的长方形=1行的个数x4行+1竖的个数x7竖（如 图），以下分四类，相加=220｝

                                                      

              1x3=5x4+2x7=34                              2x3=5x3+2x6=27

             1x4=4x4+1x7=23                               2x4=4x3=1x6=18  

              1x5=3x4+0=12                                   2x5=3x3+0=9

              1x6=2x4+0=8                                     2x6=2x3+0=6

              1x7=1x4+0=4                                     2x7=1x3+0=3

                  

               3x4=4x2+1x5=13                                      4x5=3x1+0=3

               3x5=3x2+0=6                                            4x6=2x1+0=2

               3x6=2x2+0=4                                             4x7=1x1+0=1

               3x7=1x2+0=2  

所以答案是280.

应该是这样。

Answer 2

242个