Math 10
oshua unfolded a cardboard box. The figure of the unfolded box is shown below:
A long rectangle divided along the length into 4 equal squares is shown. Along the upper edge length of the second square is shown another square, and along the lower edge length of the fourth square is shown another square. The first square from the left has two adjacent sides labeled as 3 inches each.
Which calculation will give the total surface area of the cardboard, in square inches, that was used to make the box?
a
6 × 3 × 3
b
3 × 6 × 6
c
9 × 6 × 6
d
6 × 9 × 9