Solid angle of its faces is one-sixth of that, or sr. Solid angles can also be measured in square degrees (1 sr = () square degrees), in square minutes and square seconds, or in fractions of the sphere (1 sr = fractional area), also known as spat (1 sp = 4 sr). In spherical coordinates there is a formula for the differential, where is the colatitude (angle from the North pole) and is the longitude. The solid angle for an arbitrary oriented surface S subtended at a point P is equal to the solid angle of the projection of the surface S
Solid surface then injected into the cavity of the mould. Many finishes are available including, gel coated, matte, gloss, metallic and textured. A "surface fabricator" shapes and installs functional and decorative surfaces, usually in buildings. Surface fabrication, as a distinct professional enterprise, usually involves complex tasks of surface shaping. A leading case is countertop fabrication. For interior spaces, surfaces include solid coverings or decking for floors or walls, and countertops for kitchens, bathrooms, and workspaces. Natural surfaces are composed of naturally occurring materials like wood, stone, mineral, clay, gum and resin. Synthetic surfaces contain, in addition to any natural materials, man-made substances