What describes the entire angle that indicates the taper of a surface or part?

The term that best describes the entire angle indicating the taper of a surface or part is taper angles. Taper angles refer specifically to the angle formed between the reference straight line and the line defining the taper surface. This angle is crucial in machining and design because it directly affects how parts fit together and how efficiently they can be manufactured.

In contexts like milling or turning, understanding taper angles is essential for achieving the desired dimensions and tolerances of a component. These angles are utilized in a variety of applications, such as machined parts that require a gradual reduction in diameter or width, ensuring that parts can be correctly aligned and assembled.

The other terms, while they relate to angles, do not convey the concept of tapering as accurately. Bevel angles typically refer to angles created by cutting a straight edge at a slope, perpendicular angles denote a right angle between two lines, and incline angles generally describe the angle of ascent. Therefore, taper angles is the most appropriate choice for describing the entire angle of a tapered surface or part.