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

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

2D-prism

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.

equation

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

length-prism

(ignore the switch of the variable c to b)

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

prism-eq