The missing reason for the 5th step in the proof is (a) Substitution
Determining the missing reason for the 5th step in the proof
From the question, we have the following parameters that can be used in our computation:
The two column proof
In steps (3) and (4), we have the equations for the angle ANV
So in step (4), these values are simply substituted
Using the above as a guide, we have the following:
The missing reason for the 5th step in the proof is (a) Substitution