If σ be the mass per unit area, Then,σ=2×1+1×13=1 kg/m2∴ mass of rectangle-1,m1=σA1=1×2×1=2 kgmass of rectangle-2,m2=σA2=1×1×1=1 kg∴XCM=m1+m2m1x1+m2x2=2+12×21+1×23=65 mand YCM=m1+m2m1y1+m2y2=2+12×1+1×21=65 m∴ Centre of mass=(XCM,YCM)=(65 m,65 m)