Ключевые слова: 3d, abstract, circle, collection, concept, cube, design, drawing, education, element, emblem, endless, escher, figure, geometric, geometrical, geometry, graphic, half, hexagon, icon, illusion, illustration, infinity, inscribed, isolated, line, loop, math, mathematical, mythological, object, optical, plane, round, science, set, shape, sign, simple, study, symbol, tattoo, unreal, visual,