Which type of angle is formed by two rays that point in opposite directions?

The angle formed by two rays that point in opposite directions is characterized as a straight angle. A straight angle measures 180 degrees and is formed when the two rays extend directly away from one another along the same line, effectively creating a straight path. This is distinct from other types of angles, as both rays maintain a linear alignment while diverging, thereby creating that specific measurement.

In contrast, obtuse angles are those that measure more than 90 degrees but less than 180 degrees, while reflex angles are greater than 180 degrees but less than 360 degrees. A zero angle refers to when the two rays point in exactly the same direction, resulting in no measurable angle at all. Hence, the defining characteristic of a straight angle is its formation from two rays directed in opposite orientations, establishing its place as the correct answer.