If a vertex is not shared by other corners, can it only be represented by capital letters?

Only an angle that has a vertex and is not shared by other angles can be represented by capital letters. The angle A shown in the figure below can be expressed as ∠ a, and the angle C has only one vertex and the vertices are not shared, so it can be expressed as ∠ C..

But if a vertex has multiple angles, it can't be represented and distinguished by a capital letter. As shown in the figure below, vertex B is shared by three angles, and what is needed cannot be expressed by one letter, but should be expressed by ∠ABC, ∠DBC and ∠ABC.

Extended data:

Four ways to express an angle:

1, represented by letters of both sides of the angle and the vertex of the angle, such as ∠AOB, where O is the vertex of the angle;

2, use capital letters, such as: ∠ O.

3. Write numbers in the corner, such as ∠ 1, ∠2, etc.

4, expressed in Greek letters, similar to numbers, such as ∠ α, ∠ β, etc.

References:

Baidu encyclopedia-jiao