设小正方形边长xcm,大正方形边长3/2xcm
(3/2x)^2-x^2=10
9/4x^2-x^2=10
5/4x^2=10
x^2=8 x=2√2
S长方形=(2√2)^2*3+(3√2)^2*2=24+36=60