What mistake has Noah made in his construction?
AB and AC must be equal!!
He has to draw arcs through both points and then arcs that stem from those arcs created in the first step.
if you need help with constructions try going here:
https://mathopenref.com/tocs/constructionstoc.html
The guest is correct
See this image
Since AB = AC
AD = AD
BD = CD
Then by SSS triangle BAD is congruent to triangle CAD
The angle BAD = angle CAD
So angle ABC is bisected