The Constructive Triangles Montessori material consists of five boxes each containing a variety of coloured triangle pieces used to create an array of geometric shapes. The figures themselves are hardboard with painted finishes in grey, yellow, red, blue and green, while the boxes are natural wood with a satin-touch finish. Most of the figures have a thick black line printed along one or more edges, the purpose being to align these black edges with one another to create triangles, trapezoids and polygons. A miniature version, which is about 30% smaller, is also available. For example, the rectangular box in the regular-sized set measures 26.5 x 17.5 cm, while the same box in the miniature set measures 21 x 14 cm.