10x10=100

     14x14 = 10x10+10+(11+12+13)x2+14

               = 10x10+10+ (10x3+1+2+3)x2+14

                 =100+10+(30+6)x2+14

                 =100+10+72+14=100+72+24=196

       0r14x14 = 10x10+(11+12+13+14)x2-4

               = 10x10+ (10x4+1+2+3+4)x2- 4

               =100+(40+10)x2-4=100+100-4

           =200-4=196

     25x25= 20x20+20+(21+22+23+24)x2+5x5