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People's Education Press Junior Middle School Mathematical Geometry
Solution: 2 = 2 ∠ 1

The reason for this is the following:

∫DE∨AC,DF∨AB

∴∠ 1=∠fad,∠2=∠bac;

And AD is the angular bisector of △ABC.

∴∠DAE=∠DAF=? ∠BAC

∴∠ 1=∠DAF=? ∠BAC

∴∠2=∠BAC=2∠ 1

That is ∠ 2 = 2 ∠ 1.