三角形ABC相似于三角形ADE AD/AB=3/(3+5)=3/8AE/AC=2/(1+2)=2/3(如果是）三角形ABC相似于三角形AED(AE*AC)/(AB*AD)=(2/3 AC*AC)/(3/8 AB*AB)=(16*( AC*AC))/(9*( AB*AB))=1则有AC/AB=3/4设AB=8X,可得AD=3X,DB=5X; AC...