The term 'projecting edge' is used to describe the four parts of a roof. The first part is the BRIM, which is the horizontal edge that runs around the perimeter of the roof. The second part is the LIP, which is the vertical edge that runs along the eaves of the roof. The third part is the EAVE, which is the lower edge of the roof that projects beyond the wall of the building. Finally, the fourth part is the RIM, which is the upper edge of the roof that projects beyond the wall of the building. Together, these four parts form the projecting edge of a roof.