258in squared of wrapping paper.
Step-by-step explanation:
For this question, we are trying to find the surface area of the rectangular prism, not the area inside the rectangular prism because we are wrapping the box up.
So, If we break up the rectangular prism, we will get 4 rectangles that are 20 inches by 3 inches, and 2 squares (the base and the top) that are 3 inches by 3 inches.
What we have to do know is find the area of all these pieces, then add them together.
So for the 4 rectangles:
A = l x w
= 20 inches x 3 inches
= 60 inches
Since there’s 4 rectangles we do:
60 x 4 = 240 inches
For the 2 Squares:
A = l x w
= 3 inches x 3 inches
= 9 inches
since there’s 2 squares we do:
9 x 2 = 18 inches
Then we can add these totals up for the total surface area:
240 + 18 = 258 inches squared