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Grade 1 Math Units

Unit Plan 21 (Grade 1 Math): Geometry—2D Shape Attributes

Identify and classify 2D shapes by defining attributes—sides, vertices, straight/curved, closed—and draw/label squares, rectangles, triangles, circles, and hexagons with precise mathematical language.

Dr. Michael Kester-Haynes

• 5 min read
Unit Plan 21 (Grade 1 Math): Geometry—2D Shape Attributes

Focus: Identify and describe two-dimensional shapes by defining attributes—sides, vertices (corners), straight/curved, closed; classify rectangles, squares, triangles, circles, hexagons; draw and label with precision.

Grade Level: 1

Subject Area: Mathematics (Geometry)

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

I. Introduction

Students explore 2D shapes using hands-on kits and drawing tools. They learn to name shapes and describe them by defining attributes (e.g., number of sides and vertices, straight/curved lines, closed figures) rather than non-defining ones (size, color, orientation). Emphasis is on clear mathematical language and neat labeling.

Essential Questions

  • What makes a shape a triangle, rectangle, or square?
  • How do defining attributes help me name and classify shapes?
  • How does precision (labels, counts, neat lines) improve my math communication?

II. Objectives and Standards

Learning Objectives — Students will be able to:

  1. Identify defining vs. non-defining attributes for common 2D shapes.
  2. Describe and classify shapes by number of sides and vertices, and whether lines are straight/curved and closed.
  3. Draw named shapes with specified attributes and label counts precisely.
  4. Explain how a square is a rectangle (all squares are rectangles) using attributes (equal sides, right angles).
  5. Use precise vocabulary and clear diagrams to justify classifications (MP.6).

Standards Alignment — CCSS Grade 1 (threaded across the unit)

  • 1.G.1: Distinguish between defining attributes (e.g., triangles are closed and three-sided) vs. non-defining attributes (e.g., color, orientation); build and draw shapes to possess defining attributes.
  • Mathematical Practices: MP.6 emphasized (attend to precision in language, labels, and diagrams); MP.3, MP.5 threaded.

Success Criteria — Student Language

  • I can tell which attributes define a shape and which do not.
  • I can name and draw a shape and label its sides and vertices correctly.
  • I can explain why a square is also a rectangle using attributes.