Given:
James built a bookshelf shaped like a rectangular prism.
The length of the base is 4 feet.
The width of the base is 2 feet.
The height of the bookshelf is 5 feet.
We need to determine the volume of the bookshelf.
Volume of the bookshelf:
The volume of the bookshelf can be determined using the formula,
![V=length * width * height](https://img.qammunity.org/2021/formulas/mathematics/college/ou1bnnxhtmq3ogha2tqb5px73lljizmjvj.png)
Substituting the values, we get;
![V=4 * 2 * 5](https://img.qammunity.org/2021/formulas/mathematics/high-school/2qren3vspw3hsd9mldjfi1l1uq0ey54tk9.png)
Multiplying, we get;
![V=40](https://img.qammunity.org/2021/formulas/mathematics/middle-school/81vdltz7of97wcc9qrwgkjkh1gjcqildxu.png)
Thus, the volume of the bookshelf is 40 cubic feet.