Question

name the angle in three kinds of notation.
select all that apply.
a. ∠acb
b. ∠abc or ∠cba
c. ∠b
d. ∠x
e. ∠cab

Explanation:

• For \(\angle ABC\) or \(\angle CBA\):
• The vertex - based notation for an angle requires the vertex to be in the middle. Here, the vertex of the angle is \(B\), and the two rays are \(BA\) and \(BC\). So, using the three - letter notation where the vertex is in the middle, we can write \(\angle ABC\) (with \(B\) as the vertex) or \(\angle CBA\) (since the order of the non - vertex letters can be reversed when the vertex is fixed).
• For \(\angle B\):
• When there is only one angle at a vertex, we can use the single - letter notation of the vertex. In this case, at vertex \(B\), there is only one angle (the angle we are naming), so \(\angle B\) is a valid notation.
• For \(\angle x\):
• When an angle is labeled with a lowercase letter (in this case \(x\)) inside the angle, we can use that letter to name the angle. So \(\angle x\) is also a valid notation.

Answer:

B. \(\angle ABC\) or \(\angle CBA\), C. \(\angle B\), D. \(\angle x\)