How many degrees are in a straight angle?

A straight angle is defined as an angle that measures exactly 180 degrees. This measurement represents a scenario where the two rays that form the angle point in exactly opposite directions, effectively creating a straight line. Understanding that a straight angle divides the plane into two equal halves, each half represents 90 degrees, which means that the full angle, consisting of both halves, sums to 180 degrees.

In contrast, a right angle is 90 degrees, a reflex angle is typically over 180 degrees but less than 360 degrees (such as 270 degrees), and a full circle comprises 360 degrees. Therefore, the measurement of a straight angle is distinctly 180 degrees.