The following are the unique geometric characteristics.

- A angle is created when two rays intersect.
- The intersection of the two rays is called the vertex.
- There is a standard method of labeling any angle. First
label the vertex; we choose to label it
**A**. The two rays are labeled Points**B**and**C**. - The Degree of the angle between
two rays is determined by the space between the rays.
See diagram below. One ray is horizontal thus giving us a reference point. The distance
of separation between rays
**B and C**determines the obtuse angle's value. - Is there a standard way of writing this type of angle as a mathematical
expression? The answer is yes. Here are the details: (1) All angles must
start with the
**∠**character. (2) The vertex must be the center label when writing an angle. (3) Valid obtuse angle statements in this example are**∠BAC**and**∠CAB**. - An obtuse angle is always greater than 90° but less than 180°. In the example below.