What type of angle is formed when two rays point in opposite directions?

When two rays point in opposite directions, they create a straight angle. A straight angle measures exactly 180 degrees. This is because the two rays extend in directly opposite directions, aligning to form a single straight line. In contrast, the other types of angles are defined by different degrees: an obtuse angle is greater than 90 degrees but less than 180 degrees, a right angle measures exactly 90 degrees, and an acute angle is less than 90 degrees. Therefore, the rays pointing in opposite directions unequivocally create a straight angle, making that the correct answer.