Lesson 11 Rectangles with the Same Perimeter
Let’s explore rectangles with the same perimeter.
Warm-up Number Talk: Multiply to Divide
Find the value of each expression mentally.
Activity 1 Perimeter of 16 Units
Draw as many different rectangles with a perimeter of 16 units as you can.
Calculate the area of each rectangle you draw. Explain or show your reasoning.
Activity 2 Same Perimeter, Different Area
Your teacher will give you some dot paper for drawing rectangles.
For each of the following perimeters, draw 2 rectangles with that perimeter but different areas.
12 units
20 units
26 units
34 units
Choose your own perimeter.
Cut out 1 or 2 rectangles you want to share and put them on the appropriate poster. Try to look for rectangles that are different from what other groups have already placed.
Gallery Walk: As you visit the posters with your partner, discuss something you notice and something you wonder.
Practice Problem
Problem 1
Draw two rectangles with perimeter 20 units on the grid whose areas are different. What are the areas of the rectangles?