Question

The proof below may or may not be correct. If the proof is incorrect, determine the first step number that is not justified and the reason it is not justified

Answer 1

The proof is incorrect and step number 8 is the first unjustified step due to a wrong reason

Step-by-step explanation

The justification for line 8 should be CPCTC which stands for "Corresponding Parts of Congruent Triangles are Congruent".

If two triangles are congruent, then the corresponding pieces are as well.

If we know triangle AED = triangle CFD, then the corresponding angles A and C must be congruent due to CPCTC.

To prove that AB = BC, we'll need to do a bit more work. This means there are missing parts of the two-column proof. One missing step is to prove that triangle DEB = triangle DFB.