The amount of film that needs to cover the display case is its surface area
2420 square inches of film is needed to cover each display case
<h3>How to determine the amount of film needed</h3>
The dimension of the case is given as:
26 in by 15 in by 20 in
Start by calculating the surface area of the case using:

So, we have:

Evaluate the product

Hence, 2420 square inches of film is needed to cover each display case
Read more about surface areas at:
brainly.com/question/24571594