CD^2+BD^2=16^2+12^2=400
BC^2=20^2=400
CD^2+BD^2=BC^2
△BCD为直角三角形
CD⊥AB
AD^2+CD^2=AC^2 AC=AB
(AB-BD)^2+CD^2=AB^2
(AB-12)^2+16^2=AB^2
24AB=400
AB=50/3
C(ABC)=2AB+BC=2*50/3+20
=160/3
CD^2+BD^2=16^2+12^2=400
BC^2=20^2=400
CD^2+BD^2=BC^2
△BCD为直角三角形
CD⊥AB
AD^2+CD^2=AC^2 AC=AB
(AB-BD)^2+CD^2=AB^2
(AB-12)^2+16^2=AB^2
24AB=400
AB=50/3
C(ABC)=2AB+BC=2*50/3+20
=160/3