
Step-by-step explanation
Step 1
to find the total area of a rectangular prism , do

then, for prism 1
let
length=4 in
widht=1 in
height=3 in
so, the area is

Step 2
now, for prism2 ( the bigger)
Let
length07
width=3
heigth=5
replace to find the area

Step 3
finally, add the areas to find the total

I hope this helps you