What additional information would you need to prove that δabc ≅ δdef by sss?

Option A.

Step-by-step explanation:

As per figure attached, we have to prove two triangles congruent by the postulate of SSS.

Since two corresponding sides of these triangles are congruent so additional third side should also be congruent to prove both the triangles congruent.

AC ≅ DF will complete the postulate SSS to prove both the triangles congruent.

Option A. will be the answer.

x+y=90

x=30-y=x

step-by-step explanation:

if you understand you will get the answer