Question

How much sheet metal is required to make a closed rectangular box of length 1.5 m, breadth 1.2 m, and height 1.3 m?

Answer 1

length of box = l = 1.5 m,
breadth = b = 1.2 m,
height = h = 1.3 m.

Surface area of box = 2 (l × b + b × h + l × h)

= 2 (1.5 × 1.2 + 1.2 × 1.3 + 1.5 × 1.3)

= 2 (1.80 + 1.56 + 1.95)

= 2 (5.31)

= 10.62 sqm

10.62 sqm of sheet metal will be needed to make the box.