Answers

2015-03-27T11:18:11+05:30
Length = l
breadth = b 
height = h
but here we have l+b+h = 19 cm
and for diagonal = 11


like this,
   
∴ √ l^2 + b^1 + h^2 = 11

   l^2 + b^1 + h^2 = 121

so, 
[ l + b + h ]^2 = l^2 + b^1 + h^2 + 2[lb + bh + lh]

19 ^2121 + 2[lb + bh + lh]

 
361 - 121= 2[lb + bh + lh]

2402[lb + bh + lh]

∴ surface area of cuboid box is 240 cm^2
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