After clicking on the link below, there is a drop down menu below the object, change it to "Rectangular Prism." Move the three sliders to change the size of the prism.

Experiment with finding the volume area of a rectangular prism by clicking on the image below.

Use the sliders to create a rectangular prism whose dimensions are Width 3, Depth 5, and Height 12.

Answer the following questions using the figures in the illustration above. Click on the blank space to check your answers.

Source: Surface Area and Volume, Shodor.org

• The prism has Interactive popup. Assistance may be required. _______________ 6 faces.
• To the lower right side of the prism the blank shows the prism has a volume of

  Interactive popup. Assistance may be required.

  _______________

  180 cubic units

Finding the Volume Mathematically

Click on the rectangular prism. Using your mouse, turn your prism so that the long narrow side is in the front. Its dimensions are 3 and 12. (Width and Height)

• How many square units are in this single layer of blocks or face?

  Interactive popup. Assistance may be required.

  _______________

  36 units²

• How many layers of this size are needed to construct the prism?

  Interactive popup. Assistance may be required.

  _______________

  5

• Find the total cubic units in the layers or the volume.

  Interactive popup. Assistance may be required.

  _______________

  36 x 5 = 180 cubic units

Note: The volume is in cubic units.

Turn your prism so that the shorter, but still narrow, side is in the front. Its dimensions are 3 and 5. (Width and Depth)

• Find the area of this face or layer.

  Interactive popup. Assistance may be required.

  _______________

  15 units²

• Think of the above area as a single layer of the blocks. How many layers are needed to form a prism this size?

  Interactive popup. Assistance may be required.

  _______________

  12

• Find the total cubic units in all the layers.

  Interactive popup. Assistance may be required.

  _______________

  15 x 12 = 180 cubic units

Pause and Reflect

• Looking back at your calculations above, describe how to find the volume of any rectangular prism.

  Interactive popup. Assistance may be required.

  _______________

  Multiply the length, width, and height together. The units are cubic units.

• Does it matter which dimensions you call length, width or height? Explain.

  Interactive popup. Assistance may be required.

  _______________

  No, when multiplying three numbers together the order doesn't matter, the answer is always the same.