Ключевые слова: asian, black, blackboard, blank, board, chalk, chalkboard, class, classroom, concept, difficult, education, ethnic, hands, holding, idea, learning, male, math, mathmatician, memo, men, multi racial, notebook, notepad, notes, notice board, one person, oriental, pad, paint, pen, problem, pythagoras, pythagorean, representation, school, schooling, scribble, standing, student, taking notes, teacher, texture, theorem, triangle, unrecognisable people, visual, wood, writing, young, young adult,