How is the volume of a rectangular prism calculated?

The volume of a rectangular prism is determined by multiplying its length, width, and height. This is because volume measures the amount of space an object occupies, and in the case of a rectangular prism, it is essentially a three-dimensional shape defined by these three dimensions. The formula for calculating the volume—length multiplied by width multiplied by height—reflects this relationship, capturing the volume's dependence on all three dimensions.

In contrast, the other options suggest incorrect methods. Adding length, width, and height does not account for the three-dimensional space, while just multiplying length and width only calculates the area of the base, neglecting the height altogether. The formula involving two times the sum of the dimensions does not represent volume correctly either, as it misrepresents the overall measurement of three-dimensional space. The multiplication of all three dimensions remains the correct and established way to calculate the volume of a rectangular prism.