What is the term for the angle that subtends exactly 100' of arc length along a curve?

The term "Degree of Curvature" refers specifically to the angle that subtends an arc length of exactly 100 feet along a curve. This concept is important in surveying and civil engineering as it helps in defining the sharpness or the tightness of a curve.

When discussing the degree of curvature, it provides a clear and standard measure of how a curve behaves in relation to the amount of arc it covers. By associating the angle with a fixed arc length (in this case, 100 feet), it allows surveyors to easily compare different curves and determine the necessary adjustments in design when laying out roads, railways, or other infrastructure.

In contrast, other terms such as "Radius of Curvature" refer to the radius of a circle that would have the same curvature as the given arc, not the angle itself. "Tangent Angle" typically involves the angle formed at the intersection of a tangent line with a curve, and "Sector Angle" relates to the angle that subtends a particular arc of a circle but does not specify any particular length of the arc like the degree of curvature does.

Understanding the degree of curvature is essential for ensuring that curves are designed for safety and efficiency in transportation projects.