In This Unit of Study…

Fifth-grade students use the geometric properties of sides, angles, and symmetry to classify quadrilaterals and triangles in hierarchies. For example, they conclude that squares are parallelograms because they are quadrilaterals with opposite sets of parallel and congruent sides. Students use deductive reasoning to justify their thinking about the categories into which shapes are sorted while gaining a deeper understanding of “if . . . , then . . . ” relationships. For example, if a shape is a parallelogram, then it must also be a quadrilateral.

B.E.S.T. Benchmarks:

• MA.5.GR.1.1 Classify triangles or quadrilaterals into different categories based on shared defining attributes. Explain why a triangle or quadrilateral would or would not belong to a category.

Key Concepts:

• I can discuss and explain how to use attributes to classify two-dimensional figures.
• I can make sense of the relationships between the attributes of two-dimensional figures within a category.
• I can explain why a triangle or quadrilateral would or would not belong to a category.