Answer:
- ∠B
- ∠9
- ∠ABC
- ∠CBA
Explanation:
You want the angle in the diagram named 4 different ways.
Angle naming
An angle can be named by naming its vertex (if that is unambiguous), using an angle designator, or by naming the rays that make it up. The rays can be named in either order.
- vertex: ∠B
- designator: ∠9
- rays (CW): ∠ABC
- rays (CCW): ∠CBA
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Additional comment
When multiple angles have the same vertex, a combination of vertex and designator naming can be used: ∠B1, ∠B2, .... (This method is not very commonly used.)