How many degrees are in a straight angle?

• A. 90°
• B. 180°
• C. 270°
• D. 360°

Answer: (B)

A straight angle measures exactly 180 degrees. This is the angle formed when two rays point in opposite directions, creating a straight line. In geometric terms, a straight angle represents a complete turning from one direction to its opposite, which is precisely half the full circular rotation of 360 degrees.

The answer you provided correctly identifies that a straight angle is 180 degrees, distinguishing it from other angles. For instance, a right angle measures 90 degrees, which is only a quarter of a full turn, and a reflex angle like 270 degrees exceeds the straight angle. Additionally, a full rotation, or a complete angle, encompasses 360 degrees, which is not relevant in defining a straight angle but gives context to the range of angle measurements. Understanding the properties and definitions of angles is essential for solving problems in geometry effectively.