Lesson 8 Figures Made of Prisms

    • Let’s find the volume of figures made of prisms.

Warm-up Which One Doesn’t Belong: Different Figures

Which one doesn’t belong?

  1. Unorganized figure. 3 layers of cubes. First layer, 10. Second layer, 1. Third layer, 1.
  3. Figure made of cubes. 

Activity 1 Put It Together

Problem 1

  1. Partner A, build a rectangular prism with 12 cubes.

  2. Partner B, build a rectangular prism with 10 cubes.

  3. Put your two rectangular prisms together to make one figure. What is the volume of the new figure? Explain or show your thinking.

Problem 2

Diego and Jada put together two rectangular prisms to make this figure:

Two rectangular prisms, one attached to the front of the other. 

  1. What is the volume of the figure Diego and Jada made?

  2. Which rectangular prisms could Diego and Jada each have built? Explain or show your thinking. Organize it so it can be followed by others.

Activity 2 I See Two Prisms

Find the volume of each figure. Explain or show your reasoning.

  1. Rectangular prism. 3 cubes by 5 cubes by 3 cubes. With one extra cube attached to the side. 
  2. Rectangular prism with 1 row of cubes attached at the base. 
  3. Rectangular prism with row of cubes attached at the base. 
  4. Two rectangular prisms attached on the side. 

Practice Problem

Problem 1

What is the volume of this figure? Explain or show your reasoning.

Rectangular prism with additional cubes attached to front.