Four magnetic tangram sets (red, blue, green and yellow). Each complete tangram measures 10cm square. (Magnetic Show & Tell board not included). Tangrams, puzzles made up of 7 pieces (5 triangles, a square, and a parallelogram), and can combine in various ways to develop many different mathematical concepts such as shape, symmetry, similarity, congruence, perimeter, area and fractions. They can be fun on their own, but with the right guidance, Tangrams can also be incredibly educational puzzles.