Question

find the area of card board required to make an open box of length 28 cm, breadth 0.5 m & h0.2m

Answer 1

the area of the cardboard is 28 cm×50cm×20cm=28000cm^2.
Hope this will help you.

Answer 2

length (l) = 28 cm, 0.28m
breadth (b) = 0.5 m
height (h) = 0.2m
area of cardboard required :
2h ( l x b) + lb
2 x 0.2 ( 0.28 + 0.5) + 0.28 x 0.5
0.4 (0.78)+ 0.14
0.312 + 0.14
0.452 m^2