∵图中正方形ABCD,正方形EFGH,正方形MNKT的面积分别为S1,S2,S3,∴CG=NG,CF=DG=NF,∴S1=(CG+DG)²=CG²+DG²+2CG•DG=GF²+2CG•DG,S2=GF²,S3=(NG-NF)²=NG²+NF²-2NG•NF,∵S1+S2+S3=10=GF²+2CG•DG+GF²+NG²+NF²-2NG•NF=3GF²,∴S2的值是:10/3