Ключевые слова: angle, backgrounds, centimeter, closeup, document, drawing, education, equipment, geometry, instrument, isolated, isolatedbackground, learning, length, line, mathematics, measurement, measuring, millimeter, nobody, number, objects, office, planning, plastic, protractor, ruler, scale, school, shape, simplicity, single, size, sketching, striped, studying, supplies, tool, triangle, white, work, yellow,