Shape Description & Comparison

Grade: 1st Grade

Duration: 45 minutes

Class Size: 20 students

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NGSS Alignment

Standard:

• 1.G.A.1: Distinguish between defining attributes (e.g., triangles are closed and three-sided) versus non-defining attributes (e.g., color, orientation, overall size); build and draw shapes to possess defining attributes.

Disciplinary Core Ideas (DCI):

• 1.G.A: Geometry - Reason with shapes and their attributes.

Science and Engineering Practices:

• Analyzing and Interpreting Data: Organize, represent, and interpret data with up to three categories; use tools such as Venn diagrams.

Crosscutting Concepts:

• Patterns: Identify patterns in shapes by comparing attributes such as number of sides and corners.

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Learning Objectives

By the end of this lesson, students will be able to:

1. Describe shapes using specific attributes including number of sides and corners.
2. Compare two different shapes by identifying similarities and differences in their attributes.
3. Use a Venn diagram to visually organize comparing and contrasting data of shapes.
4. Develop oral language skills by discussing shape properties in small groups.

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Materials Needed

• Shape cut-outs (triangle, square, rectangle, circle, pentagon, hexagon) — 2 sets per group
• Large Venn diagram posters or chart paper (one per group)
• Dry erase markers or sticky notes for attributes
• Whiteboard and markers
• Student notebooks or drawing paper
• Digital timer

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Lesson Procedure

1. Introduction (5 minutes)

• Engage students by showing a colorful shape cut-out. Ask: "What do you notice about this shape?" Guide students to mention attributes like sides and corners.
• Briefly review previous lessons: recognizing and naming common shapes.
• Explain that today, they will describe shapes more carefully, comparing and contrasting them using a Venn diagram.

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2. Guided Practice: Attribute Exploration (10 minutes)

• Display 2 shapes side-by-side (e.g., triangle and square).
• Ask students to observe and call out attributes such as number of sides, corners, whether the sides are equal or unequal, and open/closed shape.
• As students respond, write these on the whiteboard organized by shape.
• Highlight defining attributes vs. non-defining attributes (e.g., size, color).

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3. Group Activity: Shape Comparison with Venn Diagram (20 minutes)

• Divide the class into 5 groups of 4 students each.
• Provide each group with a pair of different shape cut-outs (for example, square & rectangle, pentagon & hexagon).
• Each group will:
  • Observe and list shape attributes on sticky notes or write with markers.
  • Use a large Venn diagram poster to sort attributes:
    • Left circle: unique attributes of shape A
    • Right circle: unique attributes of shape B
    • Intersection: shared attributes
• Encourage discussion using sentence starters:
  • "This shape has ___ sides, but that shape has ___ sides."
  • "Both shapes have ___ corners."
• Circulate and facilitate by asking guiding questions to deepen understanding.

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4. Whole Class Sharing and Discussion (7 minutes)

• Have one representative from each group present their Venn diagram.
• Ask other groups to listen and add any additional observations.
• Highlight how some attributes help to define shape categories, reinforcing NGSS Standard 1.G.A.1.

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5. Reflection and Individual Assessment (3 minutes)

• Students will draw two shapes in their notebooks and write 2-3 sentences describing their similarities and differences.
• Prompt: "Choose two shapes you like. Write what is the same and what is different about them."

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Assessment

• Formative: Observation of group discussions and participation during Venn diagram activity.
• Summative: Student reflections and written comparisons at the end of the lesson.

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Differentiation Strategies

• For advanced learners: Challenge them to include attributes like types of angles (right, acute) or side length comparisons.
• For learners needing support: Provide attribute word banks and one-on-one guidance during group work.

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Teacher Reflection Notes

• Did students distinguish defining vs. non-defining attributes?
• Were students able to use the Venn diagrams effectively to organize information?
• Adjust next lesson plan to include shape construction or exploring 3D shapes based on student engagement.

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Extensions and Connections

• Connect to art by having students create their own "shape collage" using cut-outs.
• Incorporate technology by using an interactive whiteboard app to drag and drop shape attributes into a digital Venn diagram.

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This lesson intentionally blends NGSS Geometry performance expectations with science practices of analysis and data organization, leveraging patterns and attributes to build foundational math understanding that aligns with early grade science and math interdisciplinary learning goals.