This Montessori geometry material presents a focused study of the parallelogram as a fundamental quadrilateral form. Students examine the structure and measures of the parallelogram, building precise geometric language that prepares them for later studies of rectangles, rhombi, and squares. The material introduces the sides, angles, and vertices of the parallelogram, as well as the base, perimeter, area, altitude, and diagonals. Concepts included: Sides, angles, and vertices of the parallel