Answer:
B is the vertex of the angle.
Explanation:
Given: ∠ABC
We are given an angle.
The angle is formed by two rays which starting from the same point.
The starting point is nothing but the vertex of the angle.
In the given angle ∠ABC, the rays are BA and BC. which start at the point B and formed the ∠ABC.
Therefore, B is the vertex of the angle.