How many faces does a rectangular prism have?

Hint:
In geometry, a rectangular prism can be defined as a three dimensional ($3 - D$) figure which has six rectangular faces. A solid (3-dimensional) object which has six rectangular faces. It also has the same cross-section along a length, which makes it a prism. A rectangular prism can also be called a "cuboid".

Complete Step by Step Solution:
This is a given figure of a rectangular prism which somewhat looks similar to a cuboid.

We know that rectangular prisms are also a cuboid.
Thus, it has six rectangles in a net of rectangular prisms because a rectangular prism can be defined as a three dimensional ($3 - D$) figure which has six rectangular faces.
Hence, there are $6$ faces of a rectangular prism of which all are rectangular.
Additional Information: A rectangular prism has $12$ sides, $8$ vertices and $6$ rectangular faces. All the
opposite faces of a rectangular prism are equal because they have the same cross-section along a length. Rectangular prisms can be of two types, namely right rectangular prisms and non-right rectangular prisms.

Note:
A $2 - D$ figure that can be folded to make a $3 - D$ figure is defined as the net for that particular $3 - D$ figure. Any rectangular prism can have many different nets. A rectangular prism can be defined as a three dimensional (3-D) figure which has six rectangular faces.