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 or 380 in²

Step-by-step explanation:

We are given 2 parameters in the question

A rectangular prism and a rectangular wrapping paper.

To solve the question above, we have to find the areas of these two parameters.

a) Formula for the area of the Rectangular Prism = 2(WL+ HL + HW)

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

Where

L = Length = 8 inches

W = Width = 9 inches

H = Height = 10 inches

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

= 2(72 + 80 + 90)

= 2(242)

= 484 in²

b) Formula for the area of a Rectangular shaped wrapping paper

= Length × Breadth

The wrapping paper has measurements of:

2 feet by 3 feet

Since the dimensions of the rectangular prism is in inches, we have to convert that of the rectangular prism to inches as well

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 in × 36 in

= 864 in²

The amount of square inches of wrapping paper left.

= Area of Rectangular wrapping paper - Area of Rectangular prism

= 864 in² - 484 in²

= 380 in²

step-by-step explanation: