Question

Gayatri was making a mathematical model, in which she placed 4 cubes each of edge 20cm one above another. find the surface area of the resulting cuboid

Answer 1

total cube that gayatri was placed=4
side of cube=20cm
Total surface area of cube 6a^2
T. S. A. =6*20^2
=6*400
=2400cm^2

T. S. A. of 1 cube=2400cm^2
T. S. A. of 4 cubes=2400*4=9600cm^2

surface area of resulting cuboid =9600cm^2

Answer 2

Answer:

7200 cm^2

Step-by-step explanation:

side of cube=20cm

In the cuboid formed,

length =20+20+20+20 = 80cm

its height=breadth=20cm

T.S.A of cuboid=2 (lb + bh +hl)

                           =2(80*20 + 20*20 + 80*20)

                           =2(1600 + 400 + 1600)

                           =2*3600

                           =7200 cm^2

TSA of the cubes cannot be added all together to find the TSA of cuboid due to the hidden sides when stacked together..

hope it helps..