S阴=S△DBC+S正方形CEFG-S△DFG+S△BEF
S阴=DC*BD*(1/2)+CE*CG-DG*FG*(1/2)+BE*EF
S阴=5×5×(1/2)+3×3-(3+5)×3×(1/2)+3×(5-3)×(1/2)
S阴=36.5