Ключевые слова: accuracy, angle, background, centimeter, centimeters, chalk, chalkboard, college, color, design, drafting, drawing, education, engineering, equipment, flat, geometry, green, instrument, item, knowledge, lay, learn, learning, length, line, markings, math, mathematical, mathematics, measure, measurement, measuring, millimeter, number, object, orange, precision, ruler, school, science, shape, stationery, study, supply, top, triangle, university, view,