Question

Three surfaces of a cubical box have a surface area of 42 cm2 altogether. This box is to be painted on all faces except the one face that lies on the ground.
What is the area of the box to be painted?

Answer 1

Answer:

3 faces area = 42cm²

1 surface area =42/3

or 14cm²

no of faces to be painted = 6-1

or 5

or area of the box to be painted=14cm²×5

or 70cm²

Answer 2

Answer:

70cm^2

Step-by-step explanation:

we know 3a^2=42

a^2=42/3

a=√14

so area of one face of cube is √14cm ^2

5a^2=5×(√14)^2=70cm^2

points to be noted in this question that to find the area of three faces of cubical box ,we will use the formula 3a^2 and while calculating the area of 5sides we will use the formula 5a^2.

Hope it helps