Question

Zane bought a square sheet of paper of side 16 inches to decorate a pencil box he made in craft class. The pencil box has a height of 6 inches, a width of 3 inches, and a length of 5 inches.

Approximately how many square inches of paper will be remaining if he pastes paper on to the bottom base and the four side surfaces of the pencil box without any overlap?
Answer

130 in2

145 in2

160 in2

193 in2

Answer 1

well since the SA of a rectangle prism is = 2lw + 2wh + 2lh, but since in this case it would only be one base it will look like this because it will take out on of the (lw).
So its SA = lw + 2wh + 2lh
SA = 5(3) + 2(3)(6) + 2(5)(6)
SA = 15 + 36 + 60
SA = 111
Now the problem explains the square sheet so 16 * 16 would equal the SA of that paper.
SA = 16 * 16
SA = 256
So we subtract the area of the pencil box she wants to cover from the papers area to find out the remaining paper.
256 - 111 = Remaining paper
Remaining paper = 145 in^2

Answer 2

thank-you!!