∵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