Answer:
A two-dimensional slice of a three-dimensional solid is called a cross section. Rectangular prisms have the unique property that a perpendicular cross section (a slice of the prism at a 90-degree angle) always creates a rectangle, no matter where on the prism the cross section is taken.
There are three different types of cross sections of a rectangular prism: x-axis, y-axis and z-axis cross sections, corresponding to slices along one of the three dimensions of space. The sum of these three cross sections is equal to half the surface area of the prism.
