∴∠B=∠ADE=90, BC ∨ Germany,

Bd = bm, ∴δbmd is an isosceles right triangle, ∠ BDM = 45 = ∠ A,

∴DM∥AC，

∴ quadrilateral CMDE is a parallelogram.

⑵∫AB/AC = 1/√2，AD/AE= 1/√2，

∴AB/AC=AD/AE, and ∠ Bad =∠ CAE = 45,

∴δabd∽δace，

∴CE/BD=AC/AB=√2。

⑶∠N=45，CN=√3+ 1 .

(Detailed explanation: in RT δ CDE ∠ ACE = 30.

∴de=cd÷√3,∴ca=2+2/√3=(2√3+2)/√3，

CE=2DE=4/√3，

By δ cdn ∽ δ CEA:

CD*CA=CE*CN，

CN = 2×[(2√3+2)/√3]/(4/√3)=√3+ 1)