TopRectangular Prism is a prism as it has the similar cross section along the length, it is also called a Cuboid. It can be defined as a Solid object (a 3-dimensional object) which is comprised of six faces. A face is a plane surface of a solid object whether it is top or bottom or side. These faces are rectangular in shape. A cuboid looks like a box-shaped object. An edge in a rectangular prism can be defined as a Point where two faces intersect. In other words we can define rectangular prism as a 3D object which is described by six rectangular faces. Among these six faces, two faces are considered to be located at bases of prism. Cardboard boxes can be considered as rectangular prisms which are used in a box with a slot cut as handle and boxes for model trains etc. Following figure shows a rectangular prism with top, side and bottom faces.

Let’s try to find how many edges does a rectangular prism have using following steps.

1) Euler’s formula is used in following form: V + F - E = 2.

Where 'V' is the number of vertices, 'F' is the number of faces and 'E' is the number of edges in any Geometry.

2) Rewriting the formula by taking unknown 'E' on right side and also move ‘2’ to left side. So our formula becomes:

V + F – 2 = E or,

E = V + F – 2,

Now to calculate the number of edges in a rectangular prism, above formula can be used in which

V = 8 and F = 6 and hence,

E = V + F – 2 = 8 + 6 – 2 = 12,

Thus number of edges in rectangular prism is 12.