Video and Examples
Learn how to find the volume of rectangular prisms.
Rectangular prisms
Volume is the amount of space inside a 3-dimensional figure. It is measured in cubic units. A cubic centimeter is a cube that is 1 cm wide, 1 cm long, and 1 cm high.
Another way to think of volume is to find the number of unit cubes necessary for building the figure.
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Example 1 Suppose this is a cubic unit:
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Example 2 How many unit cubes are needed to build this object? |
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Example 3 How many cubes are in this figure? |
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Example 3 shows us that a shortcut for finding the volume of a rectangular prism is to find the number of cubes on the bottom "floor" and the multiply by the number of floors.
| Volume = (number of cubes on the bottom floor) x (number of floors) Volume = Area of the base x height Volume = l • w • h |
Let's practice this shortcut with a few more examples...
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Example 4 Find the volume of this rectangular prism.
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(If you look at each layer, there are 12 cubes in each. There are 5 layers, so that would make a total of 60 cubes.) |
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Example 5 Find the volume.
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Example 6 Find the volume.
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Self-Check
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Question 1 Find the volume of this prism.
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Question 2 Find the volume.
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Question 3 Find the volume.
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