A teacher covered the exterior of a rectangular prism-shaped box that measured 8 inches by 9 inches by 10 inches using one sheet of. ... by 9 inches by 10 inches using one sheet of rectangular-shaped wrapping paper that measured 2 feet by 3 feet. ... How many square inches of wrapping paper were left over?

380 square inches

Step-by-step explanation:

Step 1

We find the Surface Area of the Rectangular Prism

The Rectangular Prism has the dimensions of Length × Width × Height = 8 inches by 9 inches by 10 inches

Surface Area of a Rectangular Prism = 2(WL+ HL + HW)

Where W = Width = 9 inches

L = Length = 8 inches

H = Height = 10 inches

Surface Area of the Rectangular Prism = 2(9 × 8 + 10 × 8 + 9 × 10)

= 2(72 + 80 + 90)

= 2(242)

= 484 square inches.

Step 2

Find the area of the Rectangular shaped wrapping paper

The wrapping paper has dimensions :

2 feet by 3 feet

We have to convert to inches first

1 foot = 12 inches

2 feet = 2 × 12 inches = 24 inches

3 feet = 3 × 12 inches = 36 inches

Area of the Rectangular shaped wrapping paper = Length × Width

= 24 inches × 36 inches

= 864 square inches

Step 3

We calculate the amount of square inches of wrapping paper left.

The Amount left over = Area of Rectangular wrapping paper - Area of Rectangular prism

= 864 square inches - 484 square inches

= 380 square inches.

Therefore, the square inches of wrapping paper left over is 380 square inches.