The line of intersection of two surfaces of a sloping roof forming an internal angle less than 180°, is known as A. Ridge B. Hip C. Valley D. None of these

The correct answer is: C. Valley

A valley is the line of intersection of two surfaces of a sloping roof forming an internal angle less than 180°. It is the lowest point on a roof, where two slopes meet. The valley is typically covered with flashing to prevent water from leaking into the building.

A ridge is the line of intersection of two surfaces of a sloping roof forming an internal angle of 180°. It is the highest point on a roof. The ridge is typically covered with shingles or metal roofing.

A hip is the line of intersection of two sloping roofs that meet at a right angle. It is located at the corner of a building. The hip is typically covered with shingles or metal roofing.

None of these is the correct answer.