You need to know what makes that
triangle ABC being similar to triangle DEF by A (angle) A (Angle) S (side)
It means that triangle DEF needs to have two similar angles with ABC and one similar angle with ABC that side has to be the non-included side:
Then:
The non-include side in:
ABC are BC and AC
DEF are DF adn EF
To make
[tex]\Delta ABC\cong\Delta DEF\text{ by AAS}[/tex]
You need:
[tex]AC\cong DF[/tex]
