Answer:
The length is 40 units.
Step-by-step explanation:
You need to use a triangle for the base then use the hypotenuse of the base as the base of the diagonal shown in the prism.
[tex]0.5*8*2=\\4*2=\\16[/tex]
The hypotenuse of the triangle of the base is 16.
[tex]0.5*16*5=\\8*5=\\40[/tex]
The diagonal shown in the prism is 40 units.