Unit Plan 35 (Grade 5 Math): Geometry Synthesis—Attributes to Hierarchies

5th graders classify and compare 2D figures by properties, build geometric hierarchies, and use coordinate geometry to verify lengths and angles. They defend classifications with precise definitions, evidence, and logical reasoning.

Unit Plan 35 (Grade 5 Math): Geometry Synthesis—Attributes to Hierarchies

Focus: Apply properties to classify figures, explain category relationships (hierarchies), and solve coordinate-geometry problems in the first quadrant.

Grade Level: 5

Subject Area: Mathematics (Geometry; Coordinate Connections)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session


I. Introduction

Students pull together everything they know about attributes (sides, angles, parallel/perpendicular, symmetry) to build classification trees and hierarchies. They justify why a figure belongs to a category (and all its parent categories) and use the coordinate plane to verify attributes (lengths along grid lines, parallel/ perpendicular to axes). Emphasis is on clear definitions, evidence, and why a hierarchy works.

Essential Questions

  • Which attributes determine a figure’s category, and how do those categories nest?
  • How can a coordinate graph help me verify attributes like equal lengths or right angles?
  • What makes a classification or hierarchy explanation convincing?

II. Objectives and Standards

Learning Objectives — Students will be able to:

  1. Describe and use attributes (e.g., number of parallel sides, equal sides, right angles) to classify 2D figures.
  2. Explain hierarchies: how a figure in one category also belongs to parent categories (e.g., every square is a rectangle and a parallelogram).
  3. Create and critique classification trees and Venn/branch diagrams using precise definitions.
  4. Use the coordinate plane (first quadrant) to plot, read coordinates, and check properties (e.g., horizontal/vertical sides, equal lengths on grid lines).
  5. Communicate reasoning with labeled diagrams, coordinates, and because statements tied to definitions.

Standards Alignment — CCSS Grade 5

  • 5.G.3: Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category.
  • 5.G.4: Classify two-dimensional figures in a hierarchy based on properties.
  • 5.G.1–2 (connection): Use a coordinate system to represent/interpret points in the first quadrant and graph points to model and check geometric properties in context.

Success Criteria — Student Language

  • I can name the attributes a figure has and use them to classify it.
  • I can explain how a figure moves up the hierarchy (e.g., square → rectangle → parallelogram → quadrilateral).
  • I can plot points and use the grid to check lengths and right angles.
  • I can give a clear because statement using the definition of the category.