Because ED‖AB, FD‖AC

So ∠BFD=∠A, ∠DEC=∠A (same angle).

Because ∠A=∠A

So ∠DEC=∠BFD

Question 2

Because ∠DFE is the external angle of △CFE.

So ∠DFE=∠C+∠E

Because AB∨CD

So ∠A=∠DFE (same angle is equal)

So ∠ A = ∠ C+∠ E.

Question 3: In this picture (according to my judgment), B near A should be H, M is the point on the included angle between E and B, and O is G, hehe. ...

Because AB∨CD

So ∠ENC=∠NMB.

Because MG and NH share ∠BMF and ∠CNE equally.

So ∠CNH=∠HNM=∠NMG=∠BMG.

So ∠NMG=∠HNM (internal angles are equal)

So MG∨NH

Question 4

Because a‖b

So ∠ 1=∠BAE

Because British Columbia

So ∠2=∠CAE

Because ∠BAC=∠BAE+∠CAE, ∠ 1 = 62, ∠ 2 = 26.

So ∠ BAC = ∠ 1+∠ 2 = 62+26 = 88.

Because AD divides ∠BAC equally

So DAE = 88/2 = 44.

Question 5 (A.D. to B.C. and point O)

Because ∠AOB=∠COD (vertex angles are equal), ∠ B+∠ C = 180.

So ∠B=∠D

Similarly ∠ A = ∠ C.

Because ∠C=∠A, ∠AOB=∠COD, OA=OD (known).

So △ABO is equal to △ △DCO(AAS).

So AB=CD

Suggestion: in the future, the narrative and drawing should be consistent, otherwise some problems can't be done, hehe. ......

Thank you for your comments from friends upstairs, hehe.

Anxious ... Why by going up one flight of stairs? If I knew, I wouldn't change it. .....