What is defined as the internal angle formed by two sloping roof sections?

The internal angle formed by two sloping roof sections is referred to as a valley. In roofing terminology, a valley is where two roof planes converge and create an angle that typically directs water runoff. This is an essential element in roof design because proper drainage is crucial to avoid potential water damage. Valleys can vary in design and are often lined or structured to enhance their effectiveness in channeling water.

The other options do not accurately describe this specific angle. The deck refers to the flat surface that underlines the roofing material. A rake generally describes the sloping edge of a gable, while a ridge is the horizontal line at the top of two sloping roof sections. Each of these terms relates to different aspects of roof structure and design but does not pertain to the angle formed where two roof sections meet.