Ключевые слова: background, blue, blueprint, board, concept, design, drawing, education, engineering, equipment, geometric, geometry, graph, graphic, grid, icon, isolated, learning, line, math, mathematics, measure, measurement, metal, number, object, office, paper, pattern, pencil, photo, plan, ruler, scale, school, science, set, sheet, sign, student, study, symbol, technology, tool, tools, white,