What is the term for the inclined external angle formed by the meeting of two sloping sides of a roof?

The term for the inclined external angle formed by the meeting of two sloping sides of a roof is known as a "hip roof." In this design, all sides of the roof slope downwards towards the walls, creating an angle at the intersection of the sloped surfaces. This type of roof is well-constructed to shed water and snow effectively, and it's often chosen for its aesthetic appeal and structural stability.

A gable roof, in contrast, has two sloping sides that meet at a peak, forming a triangular shape, which is less effective in wind-prone areas compared to the hip design. A flat roof is characterized by its level surface, eliminating the inclined angles considered in the question. Lastly, a skillion roof, or a shed roof, features a single slope without any corresponding angle formed by two sides. Each of these other roof types lacks the distinctive inclined meeting angle that defines a hip roof.