∠∠∠ACB =∠DAC，∵∠∠∠∠∴∠ ACE =∠∠ ECD = 10。

Let ∠ EHC = 80, and through BC to H, you can get ∠ HEC = 90, ∠ EHB = 100.

∠∠fac = 20，∠ACF= 10 ,∴∠AFC= 150

In other words, computational fluid dynamics =∠ AFE = 30.

Because the sum of one outer angle of a triangle is equal to the sum of two non-adjacent inner angles,

∴∠FED+∠FDE=30 ①

∠HED+∠EDH= 100 ②

∠HED+∠CED=90 ③

③-②: ∠ CED-∠ EDH =- 10 ④

④+③ De: 2 ∠ CED = 20

∴∠CED= 10