过点B做AC的平行线与CD的延长线交与M
∠ACD=∠DCB=∠M
CB=BM
△ACD相似△BDM
AD:CD=AC:BM=AC;BC=2√3:2=√3
tan∠CBA=AC ;BC =√3
∠∠CBA=60°
∠A=30°
BC=1+√3
Ac=3+√3
面积=3+2√3
(2)AC=BC=2x,AB=2√2x
∠B=∠EDB=45°
BE=√2x/2
AE=2√2x-√2x/2=3√2x/2∠
过E做EF⊥AC
∠A=∠AEF=45°
AF=FE=1.5x
CF=0.5x
CE=√10x/2
Sin角ACE=1.5x/√10x/2=3√10/10