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square of a number which is before a base number

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square of a number: n^2=(n+1)^2-(n+1)-n
                 square of a number =square of a after number-(after number)-(number)
                       example=9^2=10^2-10-9
                                            =100-10-9
                                            =100-19
                                            =81
                                      19^2=20^2-20-19
                                             =400-39
                                            =361
                                      29^2=30^2-30-29
                                             =900-30-29
                                             =841
                                      39^2=40^2-40-39
                                              =1600-40-39
                                              =1521
                                      49^2=50^2-50-49
                                            =2500-50-49
                                           =2401
                                      59^2=60^2-60-59
                                               =3600-119
                                               =3481
                                      69^2=70^2-70-69
                                             =4900-70-69
                                             =4761
                                      79^2=80^2-80-79
                                              =6400-80-79
                                             = 6241
                                      89^2=90^2-90-89
                                               =8100-90-89
                                              =7921
                                     99^2=100^2-100-99
                                             =10000-199
                                             =9801
                                     In the same way we can write square of remaining  numbers

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