Answer: she will need 108 square inches of fabric.
Step-by-step explanation:
To determine the number of square inches of fabric that she will need, we would determine the surface area of the inner part of the box. The formula for determining the surface area of a box or cuboid is expressed as
Surface area = (2lw + 2lh + 2wh)
Where
l represents length of the box = 6 inches
w represents width of the box = 3 inches
h represents height of the box = 4 inches
Therefore,
Surface area = (2 × 6 × 3) + (2 × 6 × 4) + (2 × 3 × 4) = 108 inches²
