AB=ACS⊿ABC=S⊿ABD+S⊿ACD=AB*(ED+FD)/23√2+2√6=AB*2√2/2AB=﹙3√2+2√6﹚/√2 =3+2√3
三角形的面积=1/2AB*DE+1/2AC*DF=1/2AB(DE+DF)1/2AB*2√2=3√2+2√6AB=3+2√3
