Ключевые слова: abstraction, acoustical ceiling, background, building, building area, building industry, building work, civil engineering, construction, construction engineering, counter ceiling, crosssection, cutout, development, engineering, erection, fabrication, false ceiling, false floor, flank, form, framework, hardware, hung ceiling, industry, line, material, metall, perspective, profile, project, quadrate, sectional shape, shape, square, steel shape, structure, suspended ceiling, view,