Let’s dissect this polyhedron down to 2 understandable parts:

- A 2-dimensional view of the prism; a.k.a. a trapezoid:

Following the variables of the image above, the area of the trapezoid can be simply defined as the average length of the sides multiplied by the height.

- Now this definition can be translated into the third dimension by simply multiplying by the length of the prism (l):

(ignore the switch of the variable c to b)

Therefore, the final equation for the volume (a three-dimensional quantity) is: