Ключевые слова: abstract, art, backdrop, background, banner, black, bright, computer, cube, dark, decoration, design, drawing, escher, experiment, frame, geometric, graphic, gray, icon, illusion, illustration, impossible, increasing, instrument, item, join, light, magic, mobius, optical, originally, paper, pattern, rotating, shape, square, strip, symbol, technical, test, think, threedimensional, triangle, trickery, tunnel, wall, wallpaper, white,