What is the term for the width of a circle?

The term that refers to the width of a circle is diameter. The diameter is defined as the straight line segment that passes through the center of the circle and touches two points on its boundary. This measurement represents the full width of the circle and is essentially twice the length of the radius, which is the distance from the center to any point on the circumference.

Understanding the diameter is crucial in geometry and various applications, including engineering and construction tasks related to circles and circular objects. The diameter also plays a significant role in formulas that calculate other properties of a circle, such as the circumference and area. In contrast, radius denotes only half the diameter, circumference is the total distance around the circle, and area measures the space contained within the circle.