Question

1. which of the choices is not a possibility for naming the angle? * mark only one oval angle abc angle bac angle 1 angle b angle cba

Explanation:

Step1: Recall angle - naming rules

An angle can be named by its vertex (if there is only one angle at that vertex), by three points where the middle - point is the vertex (e.g., $\angle ABC$ where $B$ is the vertex), or by a number or letter inside the angle.

Step2: Analyze each option

• $\angle ABC$: This is a valid way to name the angle with $B$ as the vertex and $A$ and $C$ as points on the rays of the angle.
• $\angle BAC$: This names an angle with $A$ as the vertex, which is not the vertex of the given angle.
• $\angle 1$: Since there is a number $1$ inside the angle, it is a valid name.
• $\angle B$: Since $B$ is the vertex and there is only one angle at point $B$, it is a valid name.
• $\angle CBA$: This is also a valid way to name the angle with $B$ as the vertex and $C$ and $A$ as points on the rays of the angle.

Answer:

B. Angle BAC