∴∠ABD=36=∠CBD=∠A,∴AD=BD=BC.

Let AD = X and CD = A-X. Then X/A = (A-X)/X. The solution is: X=(- 1+√5)a/2.

So AD=(- 1+√5)a/2.

2∶ca = 4cb = 3∠c = 90 degrees, ∴BC=5.

∴CD/CE=CA/CB=4/3,DA/EB=4/3. AB Company.

And △CDE and quadrilateral DABE have the same circumference, △ CD+CE = DA+EB+5.

Let CD=x, DA=4-X, CE=3/4X, EB=3-3/4X.

Then x +3/4X=4-X+(3-3/4X)+5. Solution: X=24/7.

So CD=24/7