Answer:
The total area that is painted yellow is 
Step-by-step explanation:
we know that
The area of the outside of the box is equal to the surface area of the box minus the area of the top
The area of the outside is

where
B is the area of the base
P is the perimeter of the base
H is the height of the box
<em>Find the area of the base B</em>

<em>Find the perimeter of the base P</em>

we have

substitute the values
