Unit 7, Lesson 21-- Comparing Area and Perimeter

Lesson 21--  Comparing Area and Perimeter

Introduction

Hello Mathematicians! Today we will be learning about comparing the area and perimeter of figures.

Think about the following questions: In your life, when might you need to find the area?  When might you need to find the perimeter?  Jot down your thoughts in your math notebook.


Interactive Visual


Interactive

Part 1 Directions:

  • Today, you will use "pentominoes" to create shapes.
  • Combine three pentominoes and create a polygon. Draw and color the new polygon in your notebook. Label as “Polygon A”.
  • For example:
  • Repeat three more times and label subsequent polygons as “Polygon B”, “Polygon C”, and “Polygon D”.

Part 2 Directions:

  • Find the area and perimeter of each polygon. Be sure to include the correct label for each measure (inches or square inches). 
  • Explain how you found the area and perimeter of your polygons.

In Your Math Notebook

Let’s get out our math journals and  work through the following application problem. Make sure you read the problem carefully, draw a picture to match your thinking and write and solve an equation.

Read, Draw, Write, DONE!

R (Read the problem carefully.)

The children's playground has a rectangular sandbox.  Each side of the sandbox measures 5 feet.  Should the playground staff find the area or perimeter of the sandbox to determine the amount of pounds of sand to fill it?  How many pounds of sand should they buy?

D (Draw a picture.)

W (Write and solve an equation.)

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Georgia Department of Education, Math