Surface Area of Right Rectangular Prisms Quick Check

4 of 54 of 5 Items
Question
Sue is wrapping books to give as gifts. Book A has a length of 6.5 inches, a width of 1 inch, and a height of 8.5 inches. Book B has a length of 5.5 inches, a width of 2 inches, and a height of 8 inches. Based on surface area, which book will require less wrapping paper?(1 point)
Responses

Book A will require less wrapping paper because its surface area is 32.75 in.2
less than the surface area of Book B.
Book A will require less wrapping paper because its surface area is 32.75 in.2
less than the surface area of Book B.

Book B will require less wrapping paper because its surface area is 1.5 in.2
less than the surface area of Book A.
Book B will require less wrapping paper because its surface area is 1.5 in.2
less than the surface area of Book A.

Book A will require less wrapping paper because its surface area is 1.5 in.2
less than the surface area of Book B.
Book A will require less wrapping paper because its surface area is 1.5 in.2
less than the surface area of Book B.

Book B will require less wrapping paper because its surface area is 0.5 in.2
less than the surface area of Book A.

1 answer

To determine which book requires less wrapping paper, we need to calculate the surface areas of Book A and Book B.

The formula for the surface area \(S\) of a right rectangular prism is:

\[ S = 2(lw + lh + wh) \]

where \(l\) is the length, \(w\) is the width, and \(h\) is the height.

For Book A:

  • Length \(l = 6.5\) inches
  • Width \(w = 1\) inch
  • Height \(h = 8.5\) inches

Calculating the surface area:

\[ S_A = 2((6.5 \times 1) + (6.5 \times 8.5) + (1 \times 8.5)) \] \[ = 2(6.5 + 55.25 + 8.5) \] \[ = 2(70.25) \] \[ = 140.5 , \text{in}^2 \]

For Book B:

  • Length \(l = 5.5\) inches
  • Width \(w = 2\) inches
  • Height \(h = 8\) inches

Calculating the surface area:

\[ S_B = 2((5.5 \times 2) + (5.5 \times 8) + (2 \times 8)) \] \[ = 2(11 + 44 + 16) \] \[ = 2(71) \] \[ = 142 , \text{in}^2 \]

Now we compare the surface areas:

  • Surface area of Book A: \(140.5 , \text{in}^2\)
  • Surface area of Book B: \(142 , \text{in}^2\)

Since \(140.5 < 142\), Book A has a smaller surface area.

Conclusion: Book A will require less wrapping paper because its surface area is \(1.5 , \text{in}^2\) less than the surface area of Book B.

The correct response is: Book A will require less wrapping paper because its surface area is 1.5 in.² less than the surface area of Book B.