Question

a cubical box opened at the top has dimensions 20 cm × 16 cm × 14 cm what is the total area of metal sheet required to make 10 such boxes​

Answer 1

Recall:

An opened box implies that the top is not covered.

The total material needed are the material needed for the other 5 surfaces.

Formula:

Area of a rectangle = Length x Breadth

Perimeter of a rectangle = 2(Length + Breadth)

Lateral Surface Area of a rectangle = Perimeter x Height

Find the area area of the base:

Area of a rectangle = Length x Breadth

Area of the rectangle = 20 x 16

Area of the rectangle = 320 cm²

Find the perimeter of the top:

Perimeter of a rectangle = 2(Length + Breadth)

Perimeter of the rectangle = 2(20 + 16)

Perimeter of the rectangle = 72 cm

Find the Lateral Surface Area:

Lateral Surface Area of a rectangle = Perimeter x Height

Lateral Surface Area of the rectangle = 72 x 14

Lateral Surface Area of the rectangle = 1008 cm²

Find the total material required for 1 box:

Material required = 320 + 1008

Material required = 1328 cm²

Find the total material required for 10 boxes:

Material required for 1 box = 1328 cm²

Material required for 10 boxes = 1328 x 10

Material required for 10 box = 13280 cm²

Answer: 13280 cm²