Whenever we want to name an angle, we use the symbol ∠. Each angle can be named in several ways. One way to name an angle is to use the letter or number that corresponds to the vertex of the angle. In this case, it is ∠B or ∠4.
Alternatively, we can place the letter name of the vertex between the name of points that lie on the rays creating the angle. We can do this in two ways by interchanging the names of the points. Here, we have A and C.
∠A B C or ∠C B A
Now let's classify the angle.
