Ключевые слова: activity, architect, back to measure, beard, bearded, calculation, classic, classroom, college, cone, copy, disciplines, education, element, elementary school, exam, formal, high, holding, learning, lesson, male, man, math, mathematics, mature, measurement, minus, outline, pass, picture, practice, prepare, protractor, ruler, school, school lesson, school subject, sinus, size, smart, student, studying, subject, task, teacher, tool, using, work,