What additional information do you need to prove △abc ≅ △def by the sss postulate?

a. bc = ef
b. ab = de
c. ac = df

The answer to this question is answer choice C.

For the SSS postulate, we need 3 pairs of congruent sides. However, in the image, there are only 2 pairs. 

The missing pair in the image is AC and DF. If those are congruent, the triangle can be proven congruent by the SSS postulate.

Hope this helps! :)

~AgentCozmo4, Junior Moderator