Current location - Training Enrollment Network - Mathematics courses - 20 12 Beijing senior high school entrance examination mathematics 19 has many solutions.
20 12 Beijing senior high school entrance examination mathematics 19 has many solutions.
For DH⊥AC in H, over D, dec = 45? ? DE=√2

∴DH=HE= 1? Similarly, ≈DCE = 30? ∴dc=2,hc=√3,ec=eh+hc=√3+ 1? ∫∠AEB = 45? ? BE=2√2? ∴AE=AB=2

∴AC=AE+EC=2+√3+ 1=3+√3? ∴S quadrilateral ABCD = s △ ABC+s △ ACD =1/2× 3+√ 3× (1+2) =1