Surface Area of Cubes and Cuboids

A cube has a surface area of 96cm².

Find the side length of the cube.

Answer explanation

$96\ \div\ 6\ =\ 16$

$\sqrt{16}\ =\ 4$

A cube has a surface area of 294 square centimeters. 
Find the side length, x, of the cube.

Answer explanation

 $296\ \div\ 6\ =\ 49$ 

 $\sqrt{49}\ =\ 7$ 

A company is designing a new box to hold cereal. They have two designs, cuboids A and B, with the same volume. The company wants to choose the smallest surface area.

Which cuboid should they choose?

• Cuboid A

• Cuboid B

• Either, they both have the same surface area.

A company is designing a new box to hold cereal. They have two designs, cuboids A and B, with the same volume. The company wants to choose the smallest surface area.

What is the difference, in cm², between the surface areas of the two boxes?

Answer explanation

Surface Area of Cuboid A is 184cm².

Surface Area of Cuboid A is 192cm².

The difference is 8cm².

The shapes are made from 1cm cubes.

What is the surface area, in cm², of the cube on the left-hand side?

Sue is covering this box with coloured paper.

She covers the two largest faces with blue paper.

Work out the area, in cm², of blue paper that she uses.

Answer explanation

30 x 20 = 600

600 x 2 = 1200 (2 largest faces)

Sue is covering this box with coloured paper.

She covers the two smallest faces with green paper.

Work out the area, in cm², of green paper that she uses.

Answer explanation

8 x 20 = 160

160 x 2 = 320 (2 smallest faces)

A cuboid is 9cm long.

It has square ends 2cm x 2cm.

Find, in cm², its total surface area.

The surface area of a cube is 150cm².

Work out, in cm², the area of one face.

Answer explanation

150cm² / 6 = 25cm²

It takes 15 litres of paint to cover the surface are of the cube on the left. How many litres paint would it take to cover the surface area of the shape on the right?

Answer explanation

15 litres, as the surface area is the same.