Question

1. which of the following is not a proper way to name the angle shown below? a. ∠acb b. ∠abc c. ∠cba d. ∠b e. ∠3

Explanation:

An angle can be named by its vertex - letter alone (if there is only one angle at that vertex), by three - letter combination with the vertex letter in the middle, or by a number assigned to the angle. In the given angle, the vertex is \(B\). The proper ways to name the angle are \(\angle ABC\), \(\angle CBA\), \(\angle B\), and \(\angle3\). \(\angle ACB\) has vertex \(C\) and represents a different angle.

Answer:

a. \(\angle ACB\)