The term "180 degrees" often refers to a half-turn in geometry, representing a straight line. In a circle, which has 360 degrees, turning 180 degrees means rotating halfway around, resulting in an opposite direction. This concept is crucial in various fields, including mathematics, physics, and engineering, where angles and rotations are essential. In everyday language, "180 degrees" can also describe a complete change in opinion or behavior. For example, if someone has a sudden shift in their views on a topic, it can be said they made a "180-degree turn." This expression highlights the contrast between their previous stance and the new one.