⬡ Montessori Sensorial Material – Constructive Triangles Small Hexagonal Box Observation & Assessment Checklist Form Understanding how shapes combine through hands-on construction. The Montessori Observation and Assessment Checklist for Constructive Triangles – Small Hexagonal Box is a carefully designed tool to help educators observe, document, and assess a child’s development of spatial awareness, geometric relationships, and logical thinking through concrete, self-correcting Montessori work.