what information is necessary to prove the triangles congruent by SAS?

Answer:
SAS requires two congruent sides and the included angle be also congruent
Given is the picture are congruent triangles
ΔACB ≅ ΔECD, because:
Answer:
The information necessary is kind of in the name
S- side A- angle S-side
You need to congruent sides and one congruent angle to prove that the triangles are congruent.
Hope this helps!