As shown in the figure, in the triangle ABC, ab = AC, take a point E on AC, take a point D on the extension line of Ba, make ad = AE, connect de and extend BC to F Whether or not it is still true to exchange the condition "ad = AE" and the conclusion "DF 8869; BC" and whether or not it is still true to exchange the condition "ad = AE" and the conclusion "DF BC" and whether or not it is still true to test the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of whether it is still true to exchange the condition "ad = AE" and the conclusion "DF BC" BC "and the condition" DF BC "and whether the condition of the condition of the condition" ad = AE "and the condition" DF BC "and whether the condition" and whether it is the condition of the exchange, whether it is the exchange, whether the condition of the condition of the condition of the condition of the exchange of the condition "and the exchange of the exchange of the exchange of the exchange of the condition" the& nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp;  

As shown in the figure, in the triangle ABC, ab = AC, take a point E on AC, take a point D on the extension line of Ba, make ad = AE, connect de and extend BC to F Whether or not it is still true to exchange the condition "ad = AE" and the conclusion "DF 8869; BC" and whether or not it is still true to exchange the condition "ad = AE" and the conclusion "DF BC" and whether or not it is still true to test the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of the test of whether it is still true to exchange the condition "ad = AE" and the conclusion "DF BC" BC "and the condition" DF BC "and whether the condition of the condition of the condition" ad = AE "and the condition" DF BC "and whether the condition" and whether it is the condition of the exchange, whether it is the exchange, whether the condition of the condition of the condition of the condition of the exchange of the condition "and the exchange of the exchange of the exchange of the exchange of the condition" the& nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp;  

In ⊿ ACG, ∫ CG ∥ DF ∥ AE / AC = ad / Ag (the parallel lines on one side of the triangle divide the other sides, and the resulting line segments are proportional) ∫ ad = AE (known) ∫ AC = Ag ∫ AB = AC () known ∫ AB = AC = Ag ∫ BCG is straight