Question

state the third congruence that must be given to prove that △def≅△abc using aas congruence theorem. de≅ab ∠d≅∠a

Explanation:

Step1: Recall AAS Congruence Theorem

AAS (Angle - Angle - Side) Congruence Theorem states that if two angles and a non - included side of one triangle are congruent to two angles and the corresponding non - included side of another triangle, then the two triangles are congruent.

Step2: Identify given information

We are given that \(DE\cong AB\) (side) and \(\angle D\cong\angle A\) (angle).

Step3: Determine the required angle

For AAS, we need one more pair of congruent angles. Since the non - included side is \(DE\) (corresponding to \(AB\)), the other pair of angles should be \(\angle E\cong\angle B\)

Answer:

\(\angle E\cong\angle B\)