The image of the triangles are missing and so i have attached it.
Answer:
Explained below.
Step-by-step explanation:
If we delete line AC in the diagram, we are left with line AB and BC.
Now, we are told to leave points B and C fixed.
Now, if we move Point A to different locations, ∠ ABC will increase or decrease depending on the new location that point A is put.
Lastly, if we move Point A to a point on line CB, it means ∠ABC = 0° because it isn't subtended at any angle at all.
