Answer:
90 square feet.
Step-by-step explanation:
Let's set up an equation!
SA= 2(xy)+2(xz)+2(yz).
Lets say that x=3 y=6 and z=3
We plug it in.
2(18)+2(9)+2(18)= SA
36+18+36=SA
72+18=SA
90=SA
90 square feet = Surface area.
