Lesson 12

Rectangles with the Same Area

Lesson Purpose

The purpose of this lesson is for students to understand that rectangles with the same area do not always have the same perimeter.

Lesson Narrative

In previous lessons, students learned to find the area and perimeter of rectangles and saw that rectangles with the same perimeter do not always have the same area. In this lesson, students draw rectangles with a specified area, find their perimeters, and notice that rectangles with the same area do not always have the same perimeter. Students then draw rectangles with specific areas that have different perimeters.

  • Action and Expression
  • MLR8

Learning Goals

Teacher Facing

  • Draw rectangles with the same area and different perimeters.

Student Facing

  • Let’s explore rectangles with the same area.

Required Materials

Materials to Gather

Materials to Copy

  • Square Dot Paper Standard

Required Preparation

Activity 2:

  • Create 4 visual displays. Each visual display should be labeled with one of the following areas: 12 square units, 20 square units, 42 square units, 48 square units.
  • Students will cut out and tape their rectangles on to one of the visual displays.

CCSS Standards

Addressing

Lesson Timeline

Warm-up 10 min
Activity 1 15 min
Activity 2 20 min
Lesson Synthesis 10 min
Cool-down 5 min

Teacher Reflection Questions

How is students’ prior understanding of area informing their understanding of perimeter and area as separate measurements of shapes?

Suggested Centers

  • Can You Draw It? (1–5), Stage 4: Area and Perimeter (Addressing)
  • Compare (1–5), Stage 4: Divide within 100 (Supporting)
  • How Close? (1–5), Stage 5: Multiply to 100 (Supporting)

Print Formatted Materials

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Additional Resources

Google Slides

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PowerPoint Slides

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