Angle Angle Side Postulate
Proving Congruent Triangles with AAS
Practice Proofs
Prove $$ \triangle ABC \cong \triangle DEC
$$
Prove $$ \triangle ABC \cong \triangle DEF
$$
Can you identify the error in the AAS proof below?
What is wrong with the proof below?
The error involves the side needed to prove two triangles congruent by the Angle Angle Side Postulate
. FE and BC are NOT full sides in either triangle. You would need to use the additon property of equality to add segment BE
to FE and BE to be able to state that their is a pair of congruent sides in the two triangles.

